GB2593503A

GB2593503A - Core training device and method

Info

Publication number: GB2593503A
Application number: GB2004311.3A
Authority: GB
Inventors: Leonard Martin Porter Luke
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-03-25
Filing date: 2020-03-25
Publication date: 2021-09-29
Anticipated expiration: 2040-03-25
Also published as: GB2593503B; GB202004311D0

Abstract

The present invention provides an exercise device 100 for exercising core muscles of a user’s torso. The exercise device 100 comprises a frame 110, configured to be supported by the user and a radially outwardly facing channel 130, the channel 130 configured to receive a resistance member 142. The frame defines an aperture (112, Fig 4) configured to receive a torso of the user and the device 100 is configured to provide a resistance force against which the user can exercise when the device 100 is in use. Also claimed is a kit of parts comprising the exercise device 100 and methods of exercising core muscles of one’s torso by turning one’s trunk relative to one’s legs to enact a force against a tangential resistance force applied to the frame.

Description

CORE TRAINING DEVICE AND METHOD

Technical Field

The disclosure relates generally to exercise devices. More particularly, the disclosure relates to portable exercise devices, and more specifically, the disclosure relates to portable exercise devices for training the core muscles of the body, and to methods for doing so.

Background

The core muscles of the torso are essential for most activities involving movement. Core muscle strength is required for a variety of sports and particularly for sports in which a club, bat or racquet is swung around the body.

Many exercise devices exist which are suitable for training the core muscles. One example is a rowing machine, with which a user simulates the motion of rowing whilst pulling a handle which provides resistance. Whilst devices such as rowing machines provide suitable pieces of equipment with which to exercise, they arc expensive and take up a large amount of space, making them unsuitable for many people. Additionally, some people may travel frequently and therefore they may require equipment which is portable.

If a user adopts a particular (bad) posture during exercise, he or she may become injured and may damage his or her muscles, which can in turn cause the user to experience pain. After sustaining an injury it is more difficult for a user to exercise, even if different muscles are being trained to those which arc injured. As such, it is important for a user to maintain a predetermined, correct, posture which reduces his or her risk of becoming injured during exercise. People who have not exercised regularly in the past may be unaware of how to position themselves if he or she wishes to avoid injury, or indeed how to position themselves to get the most effective muscle development. Some of the exercise devices which are currently available require the user to operate the device in a very specific way, which the user may be unaware of.

Low intensity exercise can be beneficial for a wide variety of people with different needs. For example, for a person who is recovering from a previous injury and is undergoing rehabilitation, high intensity exercise can cause the injury to reoccur. As such, he or she may choose to start off with low intensity exercise initially in order to prevent this. Similarly, a person who is currently injured may want to maintain his or her general fitness levels by continuing to perform low intensity exercise which will not affect the injured part of his or her body. It is therefore beneficial to be able to exercise specific muscles or muscle groups, in a controlled predictable way.

Some exercise devices which are currently available only operate within certain limits of resistance to movement and do not provide a big enough variation in difficulty to accommodate for the people of different needs. For example, some devices which operate using weights may not provide a level of exercise which accessible to people who are new to exercising certain muscles or muscle groups. in contrast, certain devices only operate at a level which is not demanding enough for an experienced user to be able to exercise properly.

An exercise device for training the core muscles that addresses at least some of the issues described above is desired.

Summary of Invention

According to an aspect of the invention there is provided an exercise device for exercising core muscles of a user's torso. The exercise device comprises a frame, configured to be supported by the user and a radially outwardly facing channel, the channel configured to receive a resistance member. The frame defines an aperture configured to receive a torso of the user and the device is configured to provide a resistance force against which the user can exercise when the device is in use.

The resistance force may be provided as a tangential force. Using a tangential force can provide the user with a uniform and/or controllable force. This can help a user with form and technique and prevent a user from 'cheating' by varying arm position or resistance during an exercise movement, The resistance force may be configurable by the user. This can allow the user to increase or decrease intensity of exercises accordingly. It can also allow the device to be used by both physically stronger and weaker users.

The exercise device may be light weight and may have a mass of less than 10kg. The exercise device may be readily picked up by a user and be transportable.

The aperture may have a diameter of between 30cm and 130cm. The aperture may be sized to fit a range of human torsos. Various iterations of the device may have varying aperture sizes in order to be used by different target users.

The channel may be situated at, proximal to, or radially inwardly displaced from a perimeter of the frame.

The channel may have a depth of at least twice the diameter of the resistance member, and preferably at least four times or six times Having a channel dcpth greater than a diameter of thc resistance member reduces the chances of the resistance member being displaced from the channel. A deeper channel can further reduce the chances of displacement.

The aperture may have a central axis that is collinear with a central axis of the frame.

Aligning the axes may provide an ergonomically preferable stance to the user and may also provide improved posture and alignment of the users limbs when exercising with the device.

The exercise device may further comprise handles for providing a device supporting means to the user.

The exercise device may comprise multiple sets of handles, and/or handles that are adjustable relative to the frame, to provide differing hand/arm position for the user when the device is in use.

Providing multiple handles, or adjustable handles, may allow different users to use the device (for example users having differing arms spans). It may also provide a user with the option to vary hi hand position in order to enact different exercise movements.

The frame may lie on a plane and the handles may extend transversely to the plane. Having the handles perpendicular, or otherwise angled to, a plane of the frame may provide a more ergonomic position for the users hands and/or arms.

The handles may be radially outwardly displaced from the aperture.

The frame may comprise a plurality of releasably attachable sections.

Having releasably attachable sections may provide the device with a means for it to be dismantled for storage and/or transport. it may also provide a means for sections of the device to be swapped or modified. For example a size of' the aperture may be modified by providing various inner sections that define different sized apertures in order to fit different user body types and sizes.

The exercise device may comprise an attachment point for attaching the resistance member to.

The attachment point may be a hole (through which the resistance member could be passed and tied or restricted by), a strut (around which the resistance member could be tied or a clip/carabiner or the like of the resistance member could be clipped) or a clip or carabiner or the like (which could attach to a corresponding loop, clip or the like of the resistance member).

When in-use, a portion of the resistance member may be seated in the channel.

The resistance member may be seated in the channel along an arc of 90° or more Seating the resistance member may provide a tangential relationship between the exercise device and a resistance point, and therefore a tangential resistance force.

The exercise device may comprise the resistance member.

The resistance member may be attached to the frame or another structural part of the device.

The resistance member may comprise a cable (band, strap, rope, or other elongate apparatus) configured to be connected to the frame and further configured to be connected to a resistance point.

The cable may be in the form of a steel rope cable commonly found in commercial gym exercise equipment, or may be of lower gauge A band may be elasticated.

The resistance member may have a length that is greater than half of a length of a perimeter of the frame. This may allow the resistance member to be seated in the channel for a full exercise movement of the user when the user is using the device.

The resistance member may be inextensible. The resistance member may be attached to an external resistance providing apparatus when in use to provide the resistance force.

The resistance member may be extensible. Extension of the resistance member may provide the resistance force.

Another aspect of the invention provides a kit of parts. The kit of parts comprises the exercise device of the preceding aspect, a resistance member and a set of instructions for providing a user with methods of using the device.

Another aspect of the invention provides a method of exercising core muscles of one's torso. The method comprises situating a frame about one's torso and supporting the frame with one's hands, applying a tangential force to the frame, and turning through an angular distance to enact a resistance force against the tangential force.

Another aspect of the invention provides a method of exercising core muscles of one's torso. The method comprises taking the exercise device of the first aspect, attaching one end of a resistance member to the exercise device, attaching another end of the resistance member to a resistance point, putting the device overhead and positioning it around one's torso, positioning oneself so that there is tension in the resistance member, twisting one's torso against the tension so as to exercise the core muscles of one's torso.

Attaching another end of the resistance member to a resistance point may comprise attaching the resistance member to an exercise machine comprising a weight and pulley system.

According to another aspect of the invention, there is provided an exercise device for exercising a user's core muscles, the exercise device comprising: a frame, wherein the frame defines a central aperture configured to receive a torso or trunk of a user: and an attachment point wherein the attachment point is configured to attach the frame to a resistance member in order to provide a resistance force against which the user can exercise when the device is in use.

The exercise device may be configured such that, in use, the resistance force is provided as a torque about a rotational axis of the frame in response to the twisting or turning his or her torso.

The torque may be a configurable torque. On other words a magnitude of the torque may be adjusted. The direction of the torque can &so be reversed so as to exercise difference muscle groups and sides of the user's body.

The torque may be configurable by adjusting a moment of inertia about a central axis of the device, or by changing the resistance of the resistance member, or by changing a resistance provided by a resistance point to which the resistance member is attached (such as a conventional pulley weight type exercise machine).

The device may further comprise fasteners which are configured to attach a first frame section to a second frame section.

The fasteners may be adjustable fasteners which are configured to vary a diameter of an inner frame section, wherein the inner frame section defines the aperture. The fasteners are adjustable through having a length that is variable, such as through a turnbuckle, strap or ratchet system.

The moment of inertia of the exercise device about the central axis of the device may be adjustable.

The frame may comprise receiving means configured to support a resistance member. That is the receiving means can both receive and support the resistance member. The receiving means may be in the form of a channel. The receiving means reduces the likelihood of the resistance member from coming unseated from the exercise device when in use as the resistance member is kept support by the receiving means.

The resistance member may be attached to, or configured to be attached to, the attachment point at a first end of the resistance member and the resistance member may be configured to be attached to an external resistance point at a second end of the resistance member.

The exercise device may comprise multiple attachments points, wherein the multiple attachment points are configured to be attached to the first end of the resistance member. The multiple attachment points may also form the receiving means in that the attachment points also attach a top section of the frame to a bottom section of the frame and the resistance member can be supported against the attachment points when the resistance member is under tension when in use.

According to another aspect of the invention there may be a kit of parts, the kit of parts comprising an exercise device according to the first aspect, and a resistance member.

The device may be configured such that when a resistance member is attached to the frame, the resistance member provides a resistance force. The resistance force may increase and decrease in response to the user twisting the exercise device. The resistance force may be applied in a direction which is substantially tangential to the perimeter of the frame. The resistance force may be applied in a direction such that a component of the force acts in a direction which is tangential to the perimeter of the frame. The resistance force may provide a torque. The torque may be generated in a direction opposite to that in which the user rotates. The user resists (i.e. provides an opposing torque to) this torque as a means of exercise. The user twists against this torque as a means of exercise.

The frame may comprise multiple attachment points. The different attachment points may be used by a user to provide exercise at different intensity levels. The resistance member may be configured to be attached to the different attachment points in order to produce different torques for the user to exercise against. The resistance member may be configured to be attached to the different attachment points in order to allow the user to exercise different muscle groups.

The frame may be configured such that an axis of rotation of the frame aligns with a central axis of the user during exercise. The frame may be configured to ensure that the user maintains a correct posture whilst exercising. The term correct posture is used throughout this application to refer to a stance during exercise wherein a user minimises his or her chance of sustaining an injury.

The frame of the exercise device may have the shape of a circle. The frame of the exercise device may have the shape of any regular polygon, any ovoid or conical section, or any irregular polygon any other irregular shapes, such as a pear shape.

The frame may comprise an inner diameter and an outer diameter. The inner diameter may be defined by the size of the central aperture of the frame The outer diameter may define the overall radial extent of the frame.

The inner diameter of the frame may range between 40cm to 100cm, or 50cm to 90cm, or between 60cm to 80cm. The inner diameter of the frame may be adjustable. The inner diameter of the frame may adjustable to enable a variety of different users to fit within the central aperture of the device.

The outer diameter of the frame may range between 70cm to 120cm, or between 80cm to 110cm, or between 85cm to 105cm. The outer diameter of the frame may be no greater than 10cm wider than an average user's arm span.

The frame of the exercise device may comprise a single frame section. The frame of the exercise device may comprise a plurality of frame sections. The frame sections may be held together via adjustable fasteners. The frame sections may be held together via rigid fasteners. The frame section with the smallest diameter may be referred to as the innermost frame section. The frame section with the largest diameter may be referred to as the outermost frame section.

The frame may comprise a first frame section and a second frame section. A diameter of the first frame section may bc smaller than a diameter of the second frame section. The first frame section may define the inner diameter of the frame. The second frame section may define the outer diameter of the frame.

The first frame section may be the innermost frame section. The second frame section may be the outermost frame section.

The innermost frame section may be configured to fit proximally around the waist of a user. The term "proximally," in this context means there is a gap between the user's waist and the innermost frame section. The gap between the user and the innermost frame section may range between Ocm and 30cm, or between Ocm and 20cm, or may range between Ocm and 10cm.

The attachment point may be attached to or formed as part of the outermost frame scction. The attachment point may be attached to or formed as part of the I0 innermost frame section. Multiple frame sections may have an attachment point attached to or formed as part of them. There may be multiple attachment points on each frame section.

The attachment point may be configured to have the resistance member tied around it. The attachment point may be configured by comprising a projecting rod around which the resistance member can be tied without the subsequent knot slipping off, such as by terminating ends of the rod into the frame. The attachment point may be configured to support a hook which is attached to the resistance member. The attachment point may be configured such that the resistance member can clip on to the frame of the exercise device. The attachment point may be configured to limit the motion of the resistance member from sliding around the frame of the exercise device. The attachment point may be configured to reduce the chance of the resistance member becoming detached from the frame when compared with a device which does not have an attachment point. The attachment point may be configured to have the resistance member attached to it through the provision of corresponding features on the resistance member and the attachment point, such as the attachment point comprise a clip (such as a carabincr) and the resistance member comprise a closed loop, or vice-versa.

A user may selectively connect the resistance member to a particular frame section in order to select a desired resistance torque to exercise against.

The component of the resistance force which acts in a tangential direction to the perimeter of the frame creates a moment about the centre of rotation of the device. This moment is proportional to the distance between the centre of rotation and the position at which the force is being applied. As such, the attachment points to which the resistance member may be attached provide a greater moment, and hence a greater torque for a user to exercise against, when he or she is positioned further from the centre of rotation of the device. The device enables the resistance member to be attached at differing radii in order to provide differing torques to the user.

The resistance member may apply a rotational force to the frame consistently around the entire perimeter of the frame. The resistance member may apply a rotational force along a continuous section of the frame. The resistance member may apply a rotational force to the innermost frame section. The resistance member may apply a rotation force to the outermost frame section. The resistance member may apply a rotational force to a frame section which does not comprise the attachment point. The resistance member may be attach to the frame via an attachment point on the first frame section and apply a rotational force to the frame via the second frame section or vice versa.

The exercise device may comprise handles. The handles may be positioned on the frame. The exercise device may alternatively comprise detachable handles. The detachable handles may be configured to be attached to or detached from the frame. The term "handles" used throughout the application may now refer to either permanent, or detachable handles. The exercise device may comprise a plurality of handles at varying distances from the centre of the device. Having detachable handles may provide a more compact storage and transport solution as well as allowing a user to position handles according to his or her preference/ according to an exercise requirement.

The handles may be positioned on the innermost frame section. The handles may be positioned on the outermost frame section. There may be handles on any of the frame sections. There may be handles positioned on multiple frame sections at the same time. There may be handles positioned at different distances from the centre of rotation of the device. The handles positioned on different frame sections may be configured to enable the user to exercise different muscles or muscle groups. The handles positioned on different frame sections may be configured to enable the user to vary the intensity of exercise he or she experiences. The handles may be positioned at various distances from the centre of the device so that users with different arm spans can reach the handles.

The handles positioned on the outermost frame reduce the force a user needs to apply to rotate the device. The handles positioned on the innermost frame sections increase the force a user needs to apply to rotate the device.

The force which the user may apply via the handles creates a moment about the centre of rotation. The moment is proportional to the distance between the centre of rotation of the device and the position at which the force which creates the moment is applied. As such, the user can apply a greater moment to the device whilst applying the same force by applying the force using handles which are positioned at a greater distance from the centre of rotation of the device.

The exercise device may comprise attachment points at various positions relative to the handles of the device. The attachment points at various positions relative to the handles may be configured to allow a user to exercise different muscles or muscle groups.

The exercise device may comprise straps attached to the frame. The straps may be configured to attach the device to the user. The straps may be configured to suspend the device from the body of the user. The straps may be configured to be worn over the shoulders of the user. The straps may be configured to support the exercise device. The straps may suspend the exercise device from the user's shoulders. The straps may enable the user to release the device without the device dropping to the floor. The straps may be adjustable straps. The straps may be non-adjustable straps. Adjustable straps may enable the user to adjust the position of the exercise device relative to the user's body. The straps may be configured to support the device relative to the user's body. The straps may be connected to, or configured to be connected to, the frame. The straps may be adjustable straps configured to vary the position of the device relative to the user's body.

The exercise device may be configured to provide a variable moment of inertia of the device. The exercise device may be configured to provide a variable moment of inertia about a central axis of the frame. The exercise device may be configured to provide a variable moment of inertia about a non-central axis of the frame. The user may vary the moment of inertia about a rotational axis of the device in order to vary difficulty of exercise experienced when using the device. The moment of inertia may be increased and decreased by respectively adding and subtracting weight from the device. I 3

The frame of the exercise device may be constructed using hollow tubes. The innermost frame section may be constructed from hollow tubes. The outer most frame section may be constructed from hollow tubes. All of the frame sections may be constructed from hollow tubes. A combination of frame sections may be constructed from hollow tubes. The frame may be constructed using hollow tubes which can be filled with a liquid such as water in order to increase the moment of inertia about an axis of rotation of the device.

The frame of the exercise device may be configured to have weights attached to it in order to increase the moment of inertia about an axis of rotation of the device. The frame may be configured such that weights can be suspended from the innermost frame section. The frame may be configured such that weights can be suspended from the outermost frame section. The frame may be configured such that weights can be suspended from any, or a combination of, frame sections.

The exercise device may comprise a resistance member attached to the frame. The resistance member may be attached to the frame via the attachment point. A first end of the resistance member may be attached to the frame. A second end of the resistance member may be configured to be attached to an external resistance point (such as a wall, a floor, a door, or a pulley system of weights).

The resistance member may be a resistance cable, such as a rope, string, an elastic cable or in some other elongate form. The resistance member may also be a closed loop, such as in an elastic band. There may be a plurality of resistance cables for a user to choose from. The different resistance members may provide different levels of resistance. Different resistance members may have different spring constants. Some resistance members may be non-extendable, meaning he or she is resistant to extension under the tension provided by ordinary human force.

The user may choose from one of the plurality of resistance members in order for the device to provide a desired torque against which the user can exercise. The resistance member may be configured to wrap around the outer perimeter of the frame multiple times to increase the tension throughout the resistance member, which would increase the torque against which the user exercises. A plurality of resistance members may be attached the frame at the same time. A plurality of resistance members may be attached to a plurality of different attachments points at the same time. A plurality of resistance members may be attached to the same attachment point at the same time.

The frame may comprise a receiving means in the form of a channel configured to receive the resistance member attached to the frame. The receiving means may prevent the resistance member from losing contact with an outer perimeter of the frame. The receiving means may be configured to support the resistance member. The receiving means may be a receiving groove. The receiving means may be present along all or most of an outer perimeter of the frame. The receiving means may prevent the resistance member from slipping off the frame and hitting the user.

The resistance point, which may be attached to the second end of the resistance member, may be a stationary resistance point. The stationary resistance point may be a wall, a floor, or an object which is sufficiently heavy such that it will not be moved by a force from the resistance member. The resistance member may comprise a loop of clip in order to be retained by the resistance point or may be simply tied and/or knotted around the resistance point (such as when the resistance member comprises a rope or band).

The resistance point which may be attached to the second end of a resistance member may be a moveable resistance point. The moveable resistance point may be a pulley weight system. The resistance point may be attached to a system such that the resistance member is configured to apply a variable force to the device. The user may increase the weight on the pulley weight system in in order to experience a greater torque to exercise against. The resistance point may be an exercise device already known in the art.

The user may attach the second end of the resistance member to a pulley weight system, and in this situation, the user may use a non-stretchable resistance member. The device may be configured to be used in combination with pre-existing devices. The user may vary the weight system in order to increase or decrease the tension throughout the resistance member. The user may increase or decrease the tension throughout the resistance member in order to experience a different amount of torque to exercise against.

The user may stand closer or further away from the resistance point in order to increase or decrease the tension throughout the resistance member. The user may choose to wrap the resistance member around the outer perimeter of the device a multiple number of times in order to increase the tension throughout the resistance member.

The user may rotate in a first direction to exercise a first group of muscles, and may rotate in a second direction to exercise a second group of muscles. The user may use the device whilst in a standing position in order to exercise. The user may keep the device substantially perpendicular to his or her upper body whilst exercising. The user may rotate the device by rotating his or her upper body only. The user may rotate the device by rotating his or her arms relative to his or her body. The user may rotate his or her body forward at the hips or knees whilst using the device in order to strengthen the specific muscle groups associated with swinging a racket, club or bat. The user may use the device in various positions in order to exercise different muscle groups The device may be configured to predominantly exercise the user's core muscles during exercise. The device may be configured to also exercise other muscles groups during exercise.

The device may be configured such that if the user accidently releases the device during exercise, it will not be repelled towards the resistance point to avoid someone being injured or something being damaged The use of the term "diameter" throughout the description and claims should be taken to mean the widest point when referring to a non-circular feature.

Brief description of the drawings

Examples of the invention will now be described, with reference to the accompanying drawings, in which: Figure 1 shows a photograph piece of exercise equipment known in the art; Figure 2 shows a photograph of another piece of exercise equipment known in the art; Figure 3 shows a photograph of an exercise device in use; Figure 4 shows a simplified plan view of the exercise device of Figure 3; Figure 5 shows a simplified front view of the exercise device of Figure 3: Figure 6 shows a simplified perspective view of the exercise device of Figure 3; Figure 7 shows a simplified front view of the exercise device of Figure 3 being prepared for use; Figure 8 shows a simplified front view of the exercise device of Figure 3 in use; Figure 9 shows a simplified front view of another exercise device in use; Figure 10 shows a simplified front view of another exercise device in use; Figure 11 shows a simplified plan view of the exercise device of Figure 9 in use; Figure 12 shows a simplified plan view of the exercise device of Figure 10 in use; Figure 13 shows a simplified plan view of another exercise device; Figure 14 shows a simplified plan view of another exercise device; Figure 15 shows a simplified plan view of an exorcise device in use by a user; Figure 16 shows a cross section of a part of an exercise device; Figure 17 shows a cross section of a part of another exercise device; Figure 18 shows a cross section of a part of another exercise device; Figure 19 shows a cross section of a part of another exercise device; Figure 20 shows a cross section of a part of another exercise device; Figure 21 shows a cross section of a part of another exercise device; Figure 22 shows a simplified plan view of an exercise device being prepared for use by a user; Figure 23 shows a simplified plan view of a user using the exercise in a first position; Figure 24 shows a simplified plan view of a user using the exercise in a second position; Figure 25 shows a simplified plan view of a user using the exercise in a third position; Figure 26 shows a simplified plan view of a user using the exercise in a fourth position; Figure 27 shows a force diagram representing the forces applied when an exercise device is in use; Figure 28 shows a simplified schematic of an exercise device in use in a first arrangement; Figure 29 shows a simplified schematic of an exercise device in use in a second arrangement; Figure 30 shows a simplified schematic of an exercise device in use in a third arrangement; I5 Figure 31 shows a simplified schematic of an exercise device in use in a fourth arrangement; Figure 32 shows a simplified schematic of an exercise device in use in a fifth arrangement: Figure 33 shows a simplified schematic of an exercise device in use in a sixth arrangement; Figure 34 shows a simplified schematic of an exercise device in use in a seventh arrangement; Figure 35 shows a simplified schematic of an exercise device in use in an eighth arrangement; and Figure 36 shows a simplified schematic of another exercise device.

Detailed Description

Figure 1 shows a first exercise machine 10 that is currently available and known in the prior art. The exercise machine is a weight and pulley based machine and comprises handles 11, cables (not visible in Figure 1 as encased within the machine), and weights 12. The cables are attached to the handles 11 at a first end and he or she is attached to the weights 12 at a second end. Various exercises can be performed using the apparatus but fundamentally each exercise consists of pulling the handles 1 to exercise against the weight of the weights 12. In one exercise a user holds the handles 1 and pulls them across his or her body. As the handles I I are pulled, the weights 12 are lifted via the cables. The weights 12 provide a resistance force through the cable 13 to the handles 11 which the user resists against as a means of exercise. The user can vary the amount of weight attached to the second of the cables 13 in order to vary the difficulty of the exercise. The user can also vary the position of the handles 1 1 relative to the user's body by adjusting pivotable arms 13 to which the handles 11 are attached.

Figure 2 shows a second exercise machine 20 that is currently available and known in the prior art, which is also a weight and pulley based machine. The second exercise machine 20 operates in operable in a similar manner to the first exercise machine 10, and also weights 22 and cables 23. The cables 23 are attached to the weights 22 (which are configurable for different resistances) at one end and to an attachment point 21 at the other end. The attachment point 21 may receive a handle of various types in dependence on a selected exercise type. In this machine 20 the user can also vary the position of the attachment points 21 (and therefore the handles) relative to the user's body through vertically raising or lowering the attachment points in order to accommodate for a range of different exercises, and to accommodate for a range of users with different heights.

in each of the prior art exercise machines 10, 20 the user is provided with control over the positioning of his or her hands and arms relative to his or her body. Whilst this freedom can provide for a variety of exercises to be performed it can also lead to injury or ineffective exercises due to poor technique and body positioning.

An example of an exercise device 100 for improving core strength is shown being used in the photograph of Figure 3. The device 100 can be used in combination with the exercise machines 10, 20 of the prior art or can be used as a standalone piece of exercise equipment A simplified, plan view of the exercise device is shown in Figure 4. The exercise device 100 comprises a frame 110 which defines a central aperture 112. A user may stand within the central aperture 112 in order to use the exercise device 100 as shown in Figure 3 The frame 110 comprises a first frame section 116 and a second frame section 118. The second frame section 118 has a greater outer diameter than the first frame section 116. An inner diameter of the first frame section 116 defines an inner diameter of the frame 110. The outer diameter of the second frame section 118 defines an outer diameter of the frame 110. The first frame section 116 and the second frame section 118 share a common central axis. in this example, in which the first and second frame sections are circular, the first frame section 116 and the second frame section 118 are therefore concentric. In other examples, the frame may comprise only a single frame section or any multiple number of frame sections. In other examples, the frame sections 116, 118 may not share a common centre.

The frame 110 is substantially circular. The first frame section 116 and the second frame section 118 are also substantially circular. In other examples the frame 110 may have another shape, such as any regular polygon or any irregular polygon, a conic section or a pear shape. Different shaped frames 110 may be used in order for the user to exercise different muscles or muscle groups with the device The inner diameter of the first frame section 116 is configured to be greater than the girth of a user, such that the user can fit his or her torso within the central aperture 112 of the frame 110. The outer diameter of the second frame section 118 is not too large so that the user can reach the second frame section 118 when he or she is positioned within the central aperture 112.

The first frame section 116 and the second frame section 118 are attached together via a plurality of fasteners 120. Figure 1 shows an example comprising eight fasteners 120, but any number of fasteners may be used instead. Preferably at least three fasteners are used. Using at least three fasteners substantially equally spaced, may provide stability of the first section relative to the second section. In the present example, the fasteners 120 are adjustable fasteners. The fasteners are adjustable through the use of a ratchet mechanism. Other adjustment systems may also be used, such as adjustable straps, turnbuckles, or any other suitable means, in other examples, the frame sections 116, 118 may be connected via non-adjustable fasteners, or a combination of adjustable and non-adjustable fasteners. The first frame section 116 is adjustable in this example, and its diameter can be varied by adjusting the adjustable fasteners 120. The diameter of the first frame section 116 may be adjusted in order to fit proximally around the differently sized waists of different users.

The first frame 116 section may comprise an elastic ring. The elastic ring may be constructed such that it has a diameter which is large enough to fit proximally around the torso of the user when there are no forces being exerted on it. The elastic ring 116 may be configured such that its diameter increases when there are forces being exerted on it via the fasteners 120. The fasteners 120 may be adjustable fasteners, and may be adjusted in order to adjust the force exerted on, and the inner diameter of, the elastic ring 116. The elastic ring 116 may be configured such that its diameter can be increased and/or decreased to a size at which it can fit proximally around the torso of users with various girths.

The frame 110 and its components (116, 118, 120) can be made from any suitable material such as plastic, wood, or metal. The materials used are sufficiently strong so that he or she does not significantly bend or deform under his or her own weight or when in use. The materials are lightweight so that a user is able to lift the device 100 without great effort. The frame 110 may be constructed using hollow tubes in order to reduce its weight. In this example the frame 100 and its components are formed from a polymer. Each part is formed from polyethylene. More specifically the outer frame section 118 is formed from high-density polyethylene and the other components are formed from low-density polyethylene. Different materials may be used in dependence on design criteria and the envisaged end user. For example, a device designed for an adult to use may be stronger (and potentially heavier) than a device designed for use by a child. Lightweight materials are preferred, having sufficient structural rigidity for the frame sections (plastics and metal, e.g. aluminium, for example).

Figure 5 shows a simplified front view of the exercise device of Figure 4. The second frame section 118 of the exercise device comprises a top section 122 and a bottom section 124. The top section is connected to the bottom section via connecting rods 126. The connecting rods in this example form a channel 130.

The exercise device comprises handles 114 attached to the frame 110. In this example a pair of handles is provided. The pair of handles provides one handle for each hand of the user. In other examples a single handle may be provided or more than two handles may be provided. A single handle may allow a single point of contact for the user, or for the user to place both hands in a central location. Multiple handles (e.g. 3, 4, 5, 6 or multiple pairs of handles) may provide a means for a user to vary his or her arm positioning, which may allow them to vary the exercise types and which muscle groups are exercised when using the device. The handles provide a means by which the user can support the exercise device 100 in position about the torso of said user. The handles 114 are connected to the second frame section 118, but in other examples, they may be connected to the first frame section 116 or any other frame section. Handles may be provided on both its first and second frame sections.

The handles 114 provide a grip for the user. The handles 114 may be profiled or coated with an appropriate material, such as rubber, in order to provide comfort for the user when grasping the handles 114. In the present example, the handles 114 are shown as protrusions extending from the second frame section 118. However, in other examples, the handles may be integrally formed as part of the frame 110. The handles 114 may be formed from indents in the frame sections (116, I 18) which are configured to receive the user's fingers. The handles 114 may be constructed from, or coated with, a material which increases the grip a user can get on the handles 114.

Figure 6 shows a simplified, perspective view of the exercise device 100 of Figures 4 and 5 in which some features have been omitted for clarity.

Figure 7 shows a simplified front view of the exercise device of figures 4-6 being prepared for use. There is a resistance member 142 attached at a first end of the resistance member 142 to one of the connecting rods 126 of the device. in this example, the end of the resistance member 142 is tied around the connecting rod 126. The connecting rod forming a connection point of the device.

Figure 8 shows a simplified front view of the exercise device of figures 4-6 in use. The resistance member 142 is wrapped around majority portion of the channel 130. The resistance member 142 abuts the connecting rods 126 in this example. The connecting rods 126 forming the channel which is configured such that the resistance member will not slip out of contact with the outer perimeter of the exercise device 100 when the resistance member is under tension. The channel is not always formed from connecting rods 126, as shown in the

example in Figure 9.

The resistance member may be supplied separately or with the frame 110 of the exercise device 100 and be attachable to the frame. The resistance member 142 may be formed integrally with the frame 110 in other examples. A first end of the resistance member 142 is attached to the frame 110 via an attachment point 140, in other examples, there may be multiple attachment points. in this example the attachment point 140 is positioned on the second frame section 118. In other examples, the attachment point(s) 140 may be positioned on the first frame section. Having multiple attachment points allows for the position of the resistance member relative to the user to be modified. This can allow for further configuration in order to account for different exercise regimes. The attachment point (or attachment points) may also be re-positionable on the frame as an alternate or supplementary means to provide further configuration options. The attachment point may be re-positionable using a clamping means, by which the attachment point clamps to the frame, or by any other suitable, releasable attachment means. Various attachment points are envisaged. The attachment point used is configured to be co-operable with the resistance member and/or vice-versa. For example, a hook-and-eye system may be used, in which the resistance member comprises a loop (i.e. the eye) at a first end and the attachment comprises a hook, peg, or similar, over which the loop may be secured. The attachment point may comprise a clamp, configured to be releasably clamped onto the first end of the resistance member, In this example, the resistance member 142 is a stretchable member, such as an elastic resistance band. The resistance force to the user twisting his or her torso is provided through stretching the resistance member. The strength required of the user to exercise with the member being proportional to the spring constant of the resistance member 142. In other examples, the resistance member 142 may be a relatively inelastic resistance cable (i.e. one that is not meant to be stretched during use), for example a steel or nylon cable such as steel wire rope often used in fixed gym equipment. In these examples resistance is generally not provided by the resistance member, but through a system (e.g. a weight or separate spring) to which the resistance member may be attached at its second end.

The second end of the resistance member 142 is configured to be attached to an external resistance point. The extern& resistance point may be stationary, fixed point such as a wall, a floor, a post, or a door handle (on a closed door) or may be a dynamic resistance point such as a pulley weight system. For an exercise device using a stretchable member a fixed resistance point is used For an exercise using an in-elastic resistance member a dynamic resistance point is used.

The resistance member 142 may be wrapped or partly wrapped around the perimeter of the frame 110 when the device is in use or when in storage. The resistance member may be wrapped around the second frame section 118 once or any number of times. Wrapping the resistance member around the device can be used to increase the tension throughout the resistance member. Wrapping the resistance member around the device also provides a storage means, by which the resistance member can be kept with the frame 110 for improved storage and transportation (compared with keeping the resistance member 142 separate from the frame 110). Wrapping the resistance member around the perimeter of the frame may apply an inwardly directed force (i.e. towards the central axis of the device) which may also assist the resistance member with locating on the device and reducing the likelihood of the resistance member becoming unseated from the device during use.

The exercise device 100 comprises a receiver which is configured to receive the resistance member 142 when the resistance member is wrapped around the frame 110. The receiver is comprised within the frame 110 in this example. The second frame section 118 comprises connecting rods (not shown in Figure 2) that form the receiver in which the resistance member 142 is held. The connecting rods connect an upper section of the frame to a lower section of the frame. When the resistance member 142 is wrapped around the frame 110, the resistance member 142 may apply a rotational force equally along the entire perimeter of the frame 110. In other examples the resistance member 142 may be partially wrapped around the perimeter of the frame 110, the resistance member 142 may apply a rotational force continuously along the section of the frame 110 which is in contact with the resistance member 142.

Figure 9 shows a simplified front view of another exercise device 200 in use. In this example, the frame 210 comprises a top section 222, a bottom section 224, and a joining section 210. The joining section 210 defines a central aperture (not shown). The joining section 210 has a curved outer perimeter which defines receiver. The device 200 comprises a connection point 226 which provides a means by which a user can attach a resistance member 142 to the device 200. The top section 222, bottom section 224 and joining section 210 can be formed from a single piece. That is the frame can be produced as a mould, such as via injection moulding or similar.

Figure 10 shows a simplified front view of another exercise device 200 in use. In this example, the frame 210 comprises a top section 222, a bottom section 224, and a joining section 210. The joining section defines a central aperture 212. The device also contains connecting rods 216 which extend between the top section 222 and bottom section 224 of the frame 210. The connecting rods 216 are curved in his or her centre towards the central aperture in order to define a deeper channel than the channel provided by the rods in the first example exercise device.

Figure 11 shows a simplified plan view of the exercise device of Figure 9. The resistance member is shown in dashed line form where it is hidden by the top section 222. The resistance member is contained within the channel and extends tangentially away from the device to a resistance point.

Figure 12 shows a simplified plan view equivalent of figure 10. In this example, the resistance member 142 is connected to a connecting rod 126 at a first end and is connected to an external resistance point (not shown) at a second end. The resistance member 142 is held taught so that the resistance member 142 rests against the channel which is defined by the connecting rods 126.

Figures 13 and 14 show simplified plan views of other exercise devices 100. In these examples, the central aperture 112 is not concentric with the centre of the exercise device 100. In these examples, the lengths of the adjustable straps 120 have been increased or decreased in order to move the first frame section 116 relative to the second frame section 118.

Figure 15 shows a simplified plan view of an exercise device 100 being used by a user 150.The user 150 is supporting the device 100 by resting the frame 110 against his or her forearms. The user 150 is holding the handles in order to exert an opposing torque on the device 100. in this example, the second end of the resistance member 142 is connected to an external resistance point 144 which is a stationary post.

Figures 16-21 shows the examples of forms of connecting rods 126 in greater detail than in earlier figures. The figures provide a cross-sectional view of the connecting rods 126. The connecting rods 126 are connected between the top section 122 and the bottom section 124 of the second frame section 118. The connecting rods 126 are configured to allow a resistance 142 member to rest against them.

The top section 122 and the bottom section 124 of the second frame section 118 are connected via the connecting rods 126. The connecting rods 126 can be curved, such that the centre of the connecting rods 126 (the centre being the point midway between the top section 122 and the bottom section 124) is closer to the centre of the exercise device 100.

The connecting rods may be constructed from any suitable material which will not break under the inwardly (i.e. towards the central axis of the frame) directed force exerted by the resistance member 142. In the example shown, the top section 122 and bottom section 124 of the second frame section are hollow In other examples the top section 122 may be hollow and the bottom section 124 may not be hollow, or vice versa. in other examples, the top and bottom sections 122, 124 may both be solid throughout.

The curvature of the connecting rods 126 creates a channel which provides a receiving means in which the resistance member 142 is received. In this example, the channel 130 is formed by the groove. In other examples, the receiving means 130 may be a receiving tube or other receiver. The channel 130 prevents the weight of the resistance member 142 from causing the resistance member 142 to fall away from the second frame section 118 The connecting rods 126 may also be used as an attachment point to attach the resistance member 142 to the device 100. In such examples, the first end of the resistance member 142 can be tied around one of the connecting rods 126 in order to connect the resistance member 142 to the exercise device 100.

In other examples the channel 130 may be constructed from a single section. The single section may be of semi-circular cross section wherein the centre of the cross section curves towards the centre of the frame 110. The semi-circular cross section may be configured to support the resistance member 142. In other examples, the single section may be of circular cross section (i.e a tube) configured to contain a portion of the resistance member 142.

The first frame section 116 (shown in Figures 1 and 2) may be constructed similarly to the second frame section 118 shown in Fig 3.

Figure 22 shows an example of a user 150 in a position ready to use the exercise device 100. The user 150 is positioned within the central aperture 112 of the frame 110. The frame 110 of the exercise device 100 is being held by the user 150 via the handles 114 which are attached to the first frame section. The first frame section is not shown in Figure 22 for clarity. The resistance member 142 is provided between the exercise device 100 and a resistance point 144. The frame 110 is being held by the user 150 at a level height with the torso of the user 150.

Figures 22-26 shows a user 150 using the device 100 to exercise. The resistance member 142 used in this example is an elastic cable. A first end of the resistance member 142 is attached to the second frame section 118 via an attachment point 140. A second end of thc resistance member 142 is attached to a resistance point 144 which is external from the exercise device 100. In the example shown, the resistance point 144 is a stationary post, which is an example of a fixed resistance point.

The user 150 in Figure 22 is facing directly towards the resistance point 144. The user 150 is stood at a distance from the resistance point 144 such that the resistance member 142 is extended beyond its natural length and so there is tension throughout the resistance member 142 which provides an elastic resistance force, but not enough tension to exert a force that can forcibly move the user 150. The user 150 may stand closer or further away from resistance point 144 in order to increase or decrease the tension throughout the resistance member 142.

The user may use different resistance members 142 to increase or decrease the tension throughout the resistance member 142. The user may use a resistance member 142 with a shorter natural length in order to increase the tension throughout the resistance member 142 without having the stand in a different position. In contrast, the user 150 may use a resistance member 142 with a greater natural length in order to decrease the tension throughout the resistance member 142 without having to stand in a different position.

Further, the user 150 may use a resistance member 142 with a greater spring constant in order to increase the tension throughout the resistance member 142.

In contrast the user 150 may use a resistance member 142 with a smaller spring constant in order to decrease the tension throughout the resistance member 142. The user may choose to increase or decrease the tension throughout the resistance member 142 in this way in order to vary the intensity of exercise he or she experiences.

In Figure 23 the user 150 has turned around through an angle of 1800 anticlockwise from the starting position in Figure 22 and has rotated the device 100 simultaneously. The user 150 grips the handles (not shown) whilst turning so that the device turns through the same angle as the user. The tension in the resistance cable 142 increases upon rotation because it extends further beyond its natural length. The tension in the resistance cable 142 produces a resistance force which acts on the second frame section 118 via the connection point (not shown), and it acts in a direction towards the fixed resistance point 144.

The component of the resistance force which acts tangentially to the perimeter of the second frame section 118 creates a clockwise torque, indicated by the arrow 152. The user 150 resists against this torque and uses it as a means of exercise. The user 150 may twist in an anti-clockwise direction to increase the amount of torque being applied or reduce the torque through twisting clockwise.

As the user twists through a greater angle, the torque applied to the device 100 increases. in this example the user twists between the positions shown in Figures 23 and 24 in order to exercise.

In order to exercise the other side of his or her body the user can turn the other way from the starting position shown in Figure 22. As shown in Figure 25 and an anti-clockwise torque 152 is provided against which the user can exercise through twisting in a clockwise direction.

By twisting it is meant that the user keeps his or her feet in position or at least does not move his or her position much, and the movement conies from turning of the torso. Such actions are common in many sports, particularly sports which involve striking -such as golf, hockey and racquet sports.

The user 150 may twist in clockwise and anti-clockwise directions periodically as a means of exercise. The user 150 may rotate through small angles to repeatedly exercise a specific muscle group. The user may rotate through larger angles to exercise a wider variety of muscle groups In other examples, the user 150 may rotate clockwise from the starting position. In such examples, the torque which the user 150 exercises against would then be in an anti-clockwise direction.

In some situations the user may turn the device through an angle greater than 360° in order to get into a starting position. In such a situation, the resistance member 142 will wrap around the perimeter of the second frame section 118. As the user 150 rotates, the resistance member 142 may be supported within the channel 130. The channel may decrease the chance of the resistance member 142 losing contact with the second frame section 118 than if the resistance member simply wrapper around a perimeter of the device In the examples shown in Figures 23-26, the user is using the centre of the device 100 as the axis of rotation. In other examples, the centre of rotation may be displaced from the centre of the device.

In other examples, the resistance member 142 may be non-extendable and the resistance point 144 may be a pulley weight system. Examples are shown in Figures 28-29. In these examples, the resistance force does not vary with the angle through which the user 150 rotates. Instead, in this example, the resistance force which is applied to the second frame section 118, and hence also the torque, is dependent on the amount of weight being lifted by the pulley weight system 144.

As the user 150 rotates the device 100, the attachment point 140 moves the resistance member 142 via the first end of the resistance member 142. The second end of the resistance member 142 is attached to the pulley weight system 144. As the user rotates, the resistance member 142 exerts a force on the pulley weight system 144 in order to lift a set of weights. The user may periodically rotate clockwise and anti-clockwise in order to repeatedly lift the weights as a means of exercise.

The non-extendable resistance member 142 is made from a material which is sufficiently strong to avoid it snapping when a large force is imposed on it from the pulley weight system.

Figure 27 shows how the moment about the centre of rotation 102 of the device 100 can vary according to which frame section 116, 118 the force is applied to. The first frame section 116 is a distance dl away from the centre of the device 100. The second frame section is a distance d2 away from the centre of the device 100.

When a force is applied to the first frame section 116 as indicated by arrow A. the moment produced about the centre of the rotation 102 of the device 100 is given by the equation: Moment = dl x Size of force A. Similarly, When a force is applied to the second frame section 118 as indicated by arrow B, the moment produced about the centre of the rotation 102 of the device 100 is given by the equation: Moment = d2 x Size of force B. As such, the same moment can be applied by applying less force when the force is applied to the second frame section 118 rather than the first frame section 116. Similarly, the same moment can be applied by applying a greater force when the force is applied to the first frame section 116 rather than the second frame section 118. A user may use handles and/or attachment points positioned on the various frame sections according to this principle.

Figures 28 and 29 show a user using the device with a weighted pulley exercise machine (which may be an exercise machine 10, 20 such as those shown in Figures 1 and 2. In Figure 28 the device has a concentric aperture to the device. In Figure 29 the aperture is off-centre. Differing the axes of the aperture and the frame can allow for different exercise types to be performed and also to provide different weight profiles. For example a circular device with a concentric aperture may provide a more uniform resistance, whereas a non-concentric aperture may provide a non-uniform resistance profile. A non-uniform resistance profile can be useful for simulating sporting movements (e.g. at different points of a swing of a racquet, club or bat) Figure 30 shows a simplified schematic of an exercise device in use with a fixed resistance point. In this example, there are straps 128 connected to the second frame section 118. The straps are being worn over the shoulders of the user 150 in order to support the device 100, in other examples, the straps 128 may be connected to any other frame section, such as the first frame section (not shown). The straps 128 are constructed from a durable fabric. Suitable materials include polyester, leather or cotton or any other suitable material. Padding may be provided on the straps in a region that is configured to sit on the user's shoulders in use in order to provide improved comfort over an unpadded strap.

The straps 128 are constructed of a material that is lightweight and that is comfortable for a user to wear. The straps 128 arc constructed to have enough tensile strength such that the straps do not distort or snap when a force is exerted on them through the weight of the device 100. The shoulder straps may be adjustable. Adjusting the shoulder straps may allow the device to be configured to fit different torso lengths. The adjustabilitv may also provide the option to position the device to exercise different muscle groups.

Figure 31 shows a simplified schematic of an exercise device 100 in use with a fixed resistance point. In this example, the central aperture 112 which receives the user is not concentric with the centre of the device 100 Figure 32 and 33 show simplified schematics of an alternative way of a user using the exercise devices in figures 30 and 31 respectively. In these examples, the user 150 has rotated his or her torso forward through a small angle in order to exercise different muscles. The user can therefore alter his or her body position to mimic the positions used in various sports.

Figures 34 and 35 show simplified schematics of a user using the exercise device in alternative ways. In these examples, the user 150 has rotated the device 100 so that it is no longer parallel with the length of the user's 150 body and instead sits around the shoulders. This can allow a user to exercise different muscles groups, such as the trapezoidal muscles.

In Figure 35, there are handles 114 above attached to the top section 122 and below attached to the bottom section 124 of the device 100. This enables a user to exercise different muscles and muscle groups. This may allow a user to replicate other sports which also require core strength but also differing movement profiles. In this case such a sport may be canoeing or kayaking, in some examples the device is not used with an external resistance point in order to provide a resistance torque. IN said a user can simply exercise against a moment of inertia of the device. In order to vary the moment of inertia the resistance member can be provided to increase mass rather than to be fixed to an external resistance point. Such an example is shown in Figure 36 shows a simplified schematic of an alternative exercise device 100. In this example, the resistance member 142 is a rope comprising weights 143. The weighted rope 142 is wrapped around the outer perimeter of the device 100 to increase the moment of inertia about the centre of the device.

Claims

CLAIMS1. An exercise device for exercising core muscles of a user's torso, the exercise device comprising a frame, configured to be supported by the user; and a radially outwardly facing channel, the channel configured to receive a resistance member, wherein the frame defines an aperture configured to receive a torso of the user, and wherein the device is configured to provide a resistance force against which the user can exercise when in use.
2. An exercise device according to claim I wherein the resistance force is a tangential force.3. An exercise device according to claim 1 or claim 2 wherein the resistance force is configurable by the user.
3. An exercise device according to any preceding claim wherein the device has a mass of less than 10kg or 20kg.
4. An exercise device according to any preceding claim wherein the aperture has a diameter of between 30cm and 130cm.
5. An exercise device according to any preceding claim wherein the channel is situated at, proximal to, or radially inwardly displaced from a perimeter of the 25 frame.
6. An exercise device according to any preceding claim wherein the channel has a depth of at least twice the diameter of the resistance member, and preferably at least four times or six times.
7. An exercise device wherein the aperture has a central axis that is collinear with a central axis of the frame.
8. An exercise device according to any preceding claim further comprising handles for providing a device supporting means to the user.
9. An exercise device according to claim 8 comprising multiple sets of handles, and/or handles that are adjustable relative to the frame, to provide differing hand/arm position for the user when the device is in use.
10. An exercise device according to claim 8 or claim 9 wherein the frame lies on a plane and the handles extend transversely to the plane.
11. An exercise device according to any one of claims 8 to 10 wherein the handles are radially outwardly displaced from the aperture.
12. An exercise device according to any preceding claim wherein the frame comprises a plurality of releasably attachable sections.
13. An exercise device according to any preceding claim wherein the exercise device comprises an attachment point for attaching the resistance member to.
14. An exercise device according to any preceding claim wherein, when in-use a portion of the resistance member is seated in the channel along an arc of 90° or more, or along an arc of at least 120°, or of at least 240°, or of at least 360°.
15. An exercise device according to any preceding claim further comprising the resistance member wherein the resistance member is attached to the frame or another structural part of the device.
16. An exercise device according to claim 15 wherein the resistance member comprises a cable (band, strap, rope, or other elongate member) configured to be connected to the frame and further configured to be connected to a resistance point
17. An exercise device according to claim 15 or claim 16 wherein the resistance member has a length that is greater than half of a length of a perimeter of the frame, or that is greater than lx, 1.5x, or 2x, or 2.5x, or 3x the length of a perimeter of the frame.
18. An exercise device according to any one of claims 15 to 17 wherein the resistance member is inextensible and wherein the resistance member is attached to an external resistance providing apparatus when in use to provide the resistance force
19. An exercise device according to any one of claims 15 to 18 wherein the resistance member is extensible and wherein extension of the resistance member provides the resistance force.
20. A kit of parts comprising: the exercise device of any one of claims 1-14 and a resistance member, or the exercise device of any one of claims 15-19; and a set of instructions for providing a user with methods of using the device.
21. A method of exercising core muscles of one's torso the method comprising: situating a frame about one's torso and holding the frame with one's hands, and optionally supporting the frame with one's hands; applying a tangential force to the frame; and turning one's trunk relative to one's legs through an angular distance to enact a resistance force against the tangential force.
22. A method of exercising core muscles of one's torso he method comprising: taking the exercise device of any one of claims 1 to 15 and attaching one end of a resistance member to the exercise device, or taking the exercise device of any one of claims 16 to 19: attaching another end of the resistance member to a resistance point; putting the device overhead and positioning it around one's torso; positioning oneself so that there is tension in the resistance member: and twisting one's torso against the tension so as to exercise the core muscles of one's torso
23. A method according to claim 22 wherein the method further comprises setting a resistance force against which one can exercise.
24. A method according to claim 23 wherein attaching another end of the resistance member to a resistance point comprises attaching the resistance member to an exercise machine comprising a weight and pulley system and setting the resistance force comprises adjusting a weight setting of the exercise machine.
25. A method according to claim 23 wherein attaching another end of the resistance member to a resistance point comprises attaching the resistance member to fixed point and wherein setting the resistance force comprises using an elasticated resistance member and varying one's position relative to the resistance point.