WO2004024240A1

WO2004024240A1 - Apparatus for plyometrics training

Info

Publication number: WO2004024240A1
Application number: PCT/GB2003/003901
Authority: WO
Inventors: Richard Robinson
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-09-16
Filing date: 2003-09-09
Publication date: 2004-03-25
Anticipated expiration: 2005-03-16
Also published as: AU2003264737A1

Abstract

Apparatus (400) for plyometric training comprises a top surface (402) at a height (h1 + h2 + h3) above the ground for contact with at least one foot of a trainer; and an inclined surface (414) extending from the top surface (402) toward the ground at an angle α for contact with at least one foot of a trainer. The apparatus (400) comprises a plurality of modules (410, 420, 430). Each module is interchangeable to allow a module to be replaced with another to allow for alteration of the angle of inclination α and height (h1 + h2 + h3).

Description

APPARATUS FOR PLYOMETRICS TRAINING TECHNICAL FIELD

The present invention relates to apparatus for plyometrics training.

BACKGROUND OF THE INVENTION

Plyometric training is specific work for the enhancement of explosive power for sportsman and woman. A training technique is used in conjunction with other power development techniques in a complete training program to improve maximum strength and explosive power. In most athletic events there is seldom enough time to develop maximum strength whereas most explosive/ballistic movements do not take that long. Therefore, to achieve the ultimate performance the athlete needs to generate the greatest possible force in the shortest period of time and reducing or stopping application of the force at the end of the action. With this objective plyometric training has a primary role in training for athletes as well as in rehabilitation programs.

Plyometric training enhances the tolerance of the muscles for increased stretch loads. This increased tolerance develops efficiency in the stretch shortening cycle of muscle action. During stretching (eccentric lengthening phase) of muscle action a greater amount of elastic energy is stored in the muscle. This elastic energy is then reused in the following concentric action to make it stronger. The key to this is a short coupling time, which is the time it takes for the muscle to switch from the lengthening/yielding phase to the shortening/overcoming work phase. This leads to the fundamental principle of plyometric training that is the rate, not the magnitude of the stretch, is what determines the utilization of chemical energy into mechanical work. One known type of commercially available plyometric training equipment comprises a plurality of stackable boxes. The boxes provide different height box jumps to improve leg power, speed and strength. An alternative to this is a box comprising four legs in which the height can be adjusted in increments to enable the user to do a full range of plyometric jumps. The problem with these types of known training equipment is that the form of training is limited to plyometric jumps which improve leg power; speed and strength do not improve agility and accuracy of the athlete's movement. A known type of commercially available plyometric training equipment which can assist an athlete in improving ability to change direction explosively is a platform comprises a pair of laterally spaced inclined surfaces providing a side to side jumping movement. An example of such training equipment is shown in Figure 1. The equipment 100 comprises a pair of facing inclined surfaces or pads 101, 102. Each pad is fixed at a predetermined angle of inclination by horizontal and vertical frame members 103, 104. The horizontal frame members 103 provide a predetermined distance between the inclined pads 101, 102. These frame members can be adjusted to provide predetermined settings of the spacing between the pads, for example by telescopic settings. The inclined pads are fixed with respect to the floor (to prevent the frame sliding) by virtue of weights 105 placed behind each inclined pad 101, 102.

The drawback of such equipment is that, although the distance between the inclined surfaces can be changed within a set number of increments, the frame does restrict the possible distances available which may be required for different sports or disciplines, the athletes' height, weight and ability. Furthermore the incline of the inclined surfaces or pads cannot be varied. Therefore, the intensity of the exercise and the muscle groups worked cannot be varied. Further, the equipment does not provide a combination of the lateral movements and the jumps to provide a more complete training program utilising a single piece of equipment. Furthermore the size of the frame does not allow easy storage of the equipment when not in use and the frame is not designed to be stationary with respect to the floor. In order to provide stability to the frame, weights are invariable placed behind each inclined surface. This is both cumbersome and makes it more difficult to set the equipment up for training.

SUMMARY OF THE INVENTION

The object of the present invention is to provide plyometric training equipment which not only develops the lateral, forward speed of an athlete, but also improves the agility and accuracy of the athletes' movements which combines plyometric jumps or steps and lateral jumping and which overcomes the aforementioned drawbacks of existing known training equipment. The equipment should be able to provide means to enable the athlete to move at high speed and intensity whilst still maintaining absolute confrol over his body and his ensuing movement.

This is achieved in accordance with an aspect of the present invention which provides apparatus for plyometric training comprising a unit, the unit comprising a top surface at a height above the ground for contact with at least one foot of a trainer; and an inclined surface extending from the top surface toward the ground at an angle for contact with at least one foot of a trainer.

In this way, the apparatus provides equipment which provides a combination of lateral movements in the athlete jumping onto the inclined surface and vertical jumps in the athlete jumping on the top surface. This enables a more complete training program to be developed.

At least two units may be positioned, when in use, at a predetermined distance apart with the inclined surfaces innermost to provide the athlete with lateral jumps for both sides (legs).

The unit may comprise at least two modules such that the modules can be interchanged to change the height of the top surface above ground and/or the angle of inclination of the inclined surface.

The equipment can assist an athlete in a wide variety of sports and disciplines such as US football, rugby, skiing, basketball, soccer, tennis and dance.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 illustrates plyometric training equipment according to the prior art;

Figure 2 illustrates a prefened embodiment of the apparatus according to the present invention;

Figures 3 a and 3b illustrate alternative parts of the apparatus shown in figure 2;

Figures 4a and 4b illustrate alternative embodiments of the apparatus according to the present invention;

Figure 5 illustrates an alternative of the prefened embodiment of the apparatus according to the present invention; and

Figures 6a to 6d illustrate examples of alternative modes of use of the apparatus according to the present invention; and Figures 7a and 7b illustrate a further alternative embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A prefened embodiment of the present invention will now be described with reference to figure 2. The apparatus according to a prefened embodiment of the present invention comprises at least one unit 200. The unit 200 comprises three modules 210, 220, 230. The unit 200 is made up of three, interlocking modules 210, 220, 230 together such that a second module 220 is sandwiched between a first and third module 210, 230.

The first module 210 comprises a top surface 202 which may be generally horizontal. The dimensions of the top surface may be approximately 55 cms square, of course, this is an illustrative example only, but the dimensions should be sufficient to allow the athlete to land safely on the surface. The shape of the top surface 202 may be square, rectangular or any other convenient shape, and any dimension suitable for allowing the athlete to jump onto the surface or, at least, contact a foot with the surface.

The top surface 202 may be coated with a shock-absorbing or cushioning material such as foam and/or a non slip material to help absorb the impact of the athlete landing on or hitting against the surface to help minimise injuries and/or to prevent the athlete slipping. Further a target can be added to the top surface 202 in the form of a red spot or cross to give the athlete a point to aim for to help improve the athlete's accuracy. A projection 204 extends outwardly from a lower surface 206 of the first module 210. The lower surface 206 is opposite the top surface 202. The projection 204 is generally of a shape conesponding to that of the top surface 202 and of a size such that a portion 208 of the lower surface 206 overhangs the projection 204. The sidewalls of 209 are perpendicular to the top surface 202. One sidewall 207 may be inclined at an angle α with respect to the horizontal as shown in figure 2 or, alternatively, this sidewall may be perpendicular to the top surface 202 as shown in figure 3 a. The top surface 202 is spaced from the lower surface 206 by a predetermined distance hi.

The second module 220 comprises an upper surface 211 and a lower surface 212. The size and shape of the upper surface 211 conesponds to the size and shape of the lower surface 206 of the first module 210. The upper surface 211 of the second module 220 is spaced from the lower surface 212 of the second module 220 by a predetermined distance h₂. The sidewalls 213 of the second module 220 are generally perpendicular to the plane of the upper and lower surfaces 211, 212 of the second module 220. One sidewall 214 of the second module 220 is inclined at an angle α with respect to the upper and lower surfaces 211, 212 of the second module 220. In the example mentioned above in respect of the first module having dimensions of 55cms square, for a height of h₂ of he second module 220 of, say, approximately 25cms and an angle of inclination α of, say, 45°, the lower surface 212 of the second module 220 would be approximately 80cms square.

The upper surface 211 of the second module 220 includes a slot 215 therein. The slot 215 of the second module 220 is of a size and shape to receive the projection 204 of the first module 210 such that the first module interlocks on the top of the second module 220. The first and second modules interlock such that the portion 208 of the lower surface 206 of the first module 210 contacts the upper surface 211 of the second module 220. The inclined surface 214 being continuous with the inclined side wall 207 of the first module 210 as shown in figure 2 or stepped with the side wall 209 of the first module 201a as shown in figure 3a. Although a projection and slot interlocking means has been shown in this embodiment, it can be appreciated that any alternative interlocking means may be utilised to prevent lateral movement of the first module relative to the second module. Examples of such alternatives are a plurality of projections and grooves or the projection extending from the upper surface of the second module to rest within a slot within the lower surface of the first module etc.

In an alternative anangement the upper surface 211 of the second module 220 may be flat, having no slot therein. The upper surface 211 of the second module 220 providing the top surface used for contact with the athlete's foot instead of the top surface 202 of the first module 210. In this anangement a first module 210 would not be utilised.

The lower surface 212 of the second module 220 includes a slot 216 therein for interlocking with the third module 230.

The surface of the inclined surface 214 of the second module 220 may be coated with a shock-absorbing or cushioning material and/or non-slip material such as foam to help absorb the impact of the athlete landing on or hitting against the surface to help minimise injuries. Further a target can be added to the inclined surface 214 of the second module 220 in the form of a red spot or cross to give the athlete a point to aim for to help improve the athlete's accuracy.

The third module 230 comprises an upper surface 221 and a lower surface 222. The lower surface 222 of the third module 230 is horizontal and is placed in contact with the floor. The surface of the lower surface 222 of the third module 230 may be roughened, grooved or coated with a non-slip material, such as rubber, or may include a plurality of non-slip pads to prevent the third module 230 from slipping with respect to the floor. Alternatively, the lower surface 222 of the third module 230 may include studs or spikes to penetrate asfro-turf or turfed surfaces etc. The upper surface 221 of the third module 230 and the lower surface 222 of the third module 230 are spaced apart by a height h₃. A projection 223 extends outwardly from the upper surface 221 of the third module 230 to engage the slot 216 of the second module 220 such that the second module rests on top of the third module 230. The size and shape of the upper surface 221 of the third module 230 conesponds to the size and shape of the lower surface 212 of the second module 220. Therefore, for the example mentioned above, the upper surface 221 of the third module 230 is approximately 80cms square.

The sidewalls 224 of the third module 230 may be perpendicular to the upper and lower surfaces 221, 222 of the third module, or alternatively one of the sidewalls may

be inclined at an angle α to provide a continuous inclined surface with the inclined surface 214 of the second module 220. The second module 220 may be used without the third module 230 and therefore non- slip pads may be attached to the lower surface 212 of the second module 220 or the surface roughened etc. to prevent the second module slipping with respect to the floor.

In an alternative embodiment the upper surface 221a of the third module 230a may be inclined at an angle β with respect to the horizontal as shown in figure 3b. One of the

sidewalls 214 of the third module 230 may also be inclined at an angle αi. The lower surface 212 of the second module 220 would then rest on the inclined upper surface 221a of the third module 230a. This would result in titling the inclined surface 214 of the second module 220 to reduce the angle of inclination α by an amount β to an

angle of inclination of αi. Although it is shown in figure 3b that one of the side walls

224a of the third module 230a is inclined at an angle oci, it can be appreciated that the side wall 224a of the alternative third module 230a may be perpendicular to the plane of the lower surface 222a of the alternative third module 230a. The shape of the projection 223a of the alternative third module 230a is maintained so that it can be inserted into the slot 216 of the second module 220.

The alternative third module 230a shown in figure 3b provides means for changing the angle of inclination α of the inclined surface 214 of the second module 220. A plurality of such alternative third modules 230a can therefore be provided with the upper surface 221a inclined at different angles of inclination β to thus provide

multiple options to change the angle of inclination α of the inclined surface 214 of the second module 220. The total height of the unit is a combination of the individual heights hi, h₂ and h₃ of each module (or at least those modules in use). Varying the height h of the second

module 220 would vary the angle of inclination α of the inclined surface 214 of the

second module 220. However, with the additional first and third modules 210 and 230, the height of the unit 200 can easily be changed by merely changing the heights hi and/or h₃ of the first and third modules 210 and 230 without affecting the angle of inclination. A plurality of first and or third modules 210, 230 can be provided at different heights to provide a full range of different-height-units so that the athlete can tailor his training needs accordingly.

Examples of assembly of the unit of the apparatus according to alternative embodiments of the present invention are shown in figures 4a and 4b.

The unit 400 as shown in figure 4a comprises a first module 410, a second module 420 and a third module 430. The first module 410 comprises a projection 404 which rests within a slot 415 of the second module 420. The third module has a projection 423 which rests within a slot (not shown here) within the base of the second module 420 to assemble the complete unit 400. The modules can then be interchanged with replacement modules to vary the height and/or angle of inclination of the inclined surface 414 of the second module 420.

The alternative unit assembly 400a shown in figure 4b comprises a first module 410a mounted on top of a second module 420a which is mounted on top of a third module 430a. The first module 410a comprises an inclined sidewall 407a which when the first module 410a is mounted on the top of the second module 420a forms a continuous slop with the inclined surface 414a of the second module 420a. The upper surface 421a of the third module 430a is inclined to tilt the inclined surface 414a of the second module 420a, thus varying the angle of inclination of the inclined surface 414a of the second module 420a. One sidewall 424a of the third module 430a is inclined to provide a continuous slop with the inclined surface 414a of the second module 420a and the sidewall 407a of the first module 410a. These alternative assemblies are merely illustrative some of the possible combinations of modules that can be fitted together to provide a full range of training equipment.

The first module 210 may also include a slot 203 in the centre of the projection 204 as shown for example in Figure 2. The slot 203 may be generally trapezoidal in shape. The slot 203 reduces the weight of the first module 210 whilst still maintaining the shape of the projection 204 for interlocking within its complementary slot 215 of the second module 220.

Furthermore, the slot 203 maybe used to receive an insert 205 as shown in Figure 5. The insert 205 has an enlarged base portion 205a. The base portion 205a is shaped to conform to the shape of the slot 203. An upper surface 205b of the base portion 205a of the insert 205 has a substantially vertical portion 205c which extends outwardly from the base portion 205 a substantially perpendicular to the upper surface 205b of the insert 205. The cross-sectional area of the vertical portion 205c is less than the cross-sectional area of the base portion 205a such that a portion 205d of the upper surface 205b of the base portion 205a extends beyond the vertical portion 205c. The portion 205d of the upper surface 205b forms a continuous surface with the outer surface of the proj ection 204 of the first module 210. In use, the first module 210 is inverted such that its upper surface 202 is in contact with the floor. Preferably, the upper surface 202 of the first module 210 is coated with a non-slip material or has non-slip pads attached thereto to prevent slippage of the module when in use. The insert 205 is placed within the slot 203 such that the vertical portion 205c extends generally upwards from the cenfre of the projection 204 of the first module 210. The insert 205 forms a hurdle which the athlete can jump over for training purposes.

Preferably, the insert 205 is formed of a shock-absorbing material such as foam to minimise injuries. The base portion 205a of the insert 205 may be designed to tip out of the slot 203 if hit by the athlete to avoid injuries to the athlete in the event that the athlete accidentally hits the insert 205.

The height of the vertical portion 205c of the insert 205 can be varied by providing a plurality of inserts 205 having different heights of the vertical portion 205c.

Figures 6a and 6b illustrate examples of the possible anangements of a plurality of units of the prefened embodiments of the invention which can provide a wider range of training facilities. Figure 6a illustrates a pair of units 500a and 500b which are spaced apart with the inclined surfaces 514a and 514b of each unit 500a and 500b facing innermost and toward each other. The pair of units 500a and 500b may be aligned so that the sidewalls 513a and 513b either side of the inclined surface 514a and 514b are in alignment. The athlete can then step or jump laterally between the units 500a and 500b bitting at least one foot on each inclined surface. This can be extended by positioning a series of such units 500c, 500d, 500e, 500f, 500g, 500h, 500i, 500j in a line as illustrated in figure 6b. The pairs of units 500c and 500d etc. are staggered such that the sidewalls either side of the inclined surface are not in alignment and the athlete can step or jump laterally between each pair of units whilst moving forward to contact each inclined surface of each unit in a sequence such as 500c to 500d to 500e to 500f to 500g to 500h to 500i and 500j.

Figures 6c and 6d illustrate further examples of possible arrangements of embodiments of the present invention to provide different jumping-type plyometrics, the units 600a, 600b, 600c, 600d, 600e can be ananged in an alignment with spacings therebetween. Each alternate unit 600a, 600c, 600e comprises a plyometric training unit comprising the top surface and inclined surface as shown in Figure 2 and the remaining units 600b, 600d may comprises the first module and insert anangement shown in Figure 5. The anangement shown in Figure 6c is purely illustrative of one possible anangement of these different forms of units. Of course, it can be appreciated that any number of units may be utilised with varying combinations of anangements with units of different heights and different spacings therebetween. The athlete can then jump on the top of the units 600a, 600c and 600e and jump over the inserts (hurdles) of the alternative units 600b and 600d.

To combine jumping plyometrics with lateral plyometrics, the basic anangement of the units 500a and 500b illustrated in Figure 5a can be combined such that the space between the units 500a and 500b can be filled with at least one "hurdle" unit 600f, 600g, 600h, 600i, 600j and 600k having an insert ananged as shown in Figure 5. Although 6 units 600f to 600k are illustrated here, it can be appreciated that any number of these units may be utilised, the spacing between the outer units 5000a and 500b is adjusted accordingly.

With this anangement, the athlete hurdles the inner units 600f to 600k for jumping plyometric training and uses the outer units 500a and 500b for lateral plyometric training purposes.

A further prefened embodiment of the present invention will now be described with reference to figures 7a and 7b. The apparatus comprises at least one unit 700. The unit 700 comprises two modules 710, 720. The unit is made up, as illustrated in figure 7b, of interlocking the two modules 710 and 720 together such that a first module 720 is mounted onto a second module 710.

The second module 710 comprises a top surface 702 which is generally horizontal and rectangular in shape. The top surface 702 of the second module 710 comprises a plurality of slots 704a to 704d. As shown in figure 7a, the top surface 702 of the second module 710 has 4 slots 704a to 704d. Of course, it can be appreciated that the top surface 702 of the second module 710 may comprise any number of slots. The sides 706 of the second module 710 are generally vertical and perpendicular to the plane of the top surface 702 of the second module 710. The lowermost surface 708 of the second module 710 is in contact with the floor and provides non-slip contact with floor, for example, the lowermost surface 708 of the second module 710 is coated with a non-slip material. The second module 710 has a height hi. The first module 720 comprises a lower surface 712 which comprises a plurality of projection 714a to 714d. The size and position of projections 714a to 714d conespond to the slots 704a to 704d of the second module 710. The first module 720 further comprises an upper surface 716, a part of which forms a top surface of the unit 700. The upper surface 716 of the first module extends from the top surface of the unit 700 toward ground at an angle of inclination α, forming the inclined surface of the unit 700. The upper surface 716 of the first module 720 further extends inwardly toward a sidewall 706 of the second module 710. This portion of the upper surface 716 of the first module 720 contacts the floor. The height between the lower surface of712 ofthe first module 720 and the portion of the upper surface 716 contacting the floor conesponds to the height hi of the second module 710. The difference between the lower surface 712 and the portion of the upper surface 716 forming the top surface of the unit 700 is a height h₂.

The total height hi + h₂ of the unit 700 can be varied by utilising different first and second module 720 and 710 having different heights hi and h₂. The angle of inclination α of the inclined surface can be varied by placing a different first module 720 onto the second module 710 having different angles of inclination. At least part of the upper surface 716 of the first module 720 may be roughened or coated with a non-slip material to prevent the user slipping on surfaces etc. A target may also be added to the inclined and/or top surface of the unit 700.

In use, as illustrated in figure 7b, the first module 720 is interlocked onto the second module 710 by interengagement of the projections 714a to 714d of the first module 720 and the slots 704a to 704d of the second module 710. It can be appreciated that other types of interlocking mechanisms may be used here. For example, the projection(s) may extend from the top surface 702 of the second module 710 to interlock a complimentary slot within the lower surface 712 of the first module 720 or the first and second modules 720 and 710 may interlock by means of clips or other suitable means.

Furthermore, it can be appreciated that the unit described with reference to any one of the above embodiments can be utilised with the top surface only for jumps during training. This could be achieved by turning the unit sideways on or, for example, the first module 720 of figures 7a and 7b may be replaced with a rectangular module having no inclined surface extending therefrom. Alternatively, a further module could be added on top of the first module 720 using suitable interlocking means to provide a higher top surface and a lower inclined surface. This alternative would therefore give the user the option of both lateral and jump training with emphasis on jumps.

Any one of the modules and/or inserts may also include identification means such that the module and inserts of different heights and different angles of inclination can easily be distinguished. In a prefened embodiment the modules and inserts are colour-coded.

Although prefened embodiments of the apparatus of the present invention has been illustrated in the accompanying drawings and described in the forgoing detailed description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous variations, modifications without departing from the scope of the invention as set out in the following claims.

Claims

CLAIMS:

1. Apparatus for plyometric training comprising a unit, the unit comprising: a top surface at a height above the ground for contact with at least one foot of a trainer; and an inclined surface extending from the top surface toward the ground at an angle for contact with at least one foot of a trainer.

2. Apparatus according to claim 1, wherein, in use, the apparatus comprises at least two units positioned a predetermined distance apart with the inclined surface of the at least two units facing innermost such that the inclined surface of a first unit faces the inclined surface of a second unit.

3. Apparatus according to claim 2, wherein the first unit is aligned with the second unit.

4. Apparatus according to claim 2, wherein the first unit is staggered with respect to the second unit.

5. Apparatus according to any one of the preceding claims wherein the angle of inclination of the inclined surface is variable.

6. Apparatus according to any one of the preceding claims, wherein the height of the top surface above the ground is variable.

7. Apparatus according to any one of the preceding claims wherein the top surface and the inclined surface are covered with a shock-absorbing or cushioning material and/or non-slip material.

8. Apparatus according to any one of the preceding claims wherein the top and/or inclined surface have a target thereon.

9. Apparatus according to any of the preceding claims, wherein the unit comprises a first module and a second module, the first and second modules being separable.

10. Apparatus according to claim 9, wherein the first module includes the top surface and the second module includes a substantial portion of the inclined surface.

11. Apparatus according to claim 9 or 10, wherein, the first and/or second modules can be used separately.

12. Apparatus according to any one of claims 9 to 11, wherein the first and second modules further comprise interlocking means to interlock the modules together to form the unit.

13. Apparatus according to any one of claim 9 to 12, wherein the apparatus further comprises a third module which in combination with the first and/or second module forms the unit.

14. Apparatus according to claim 13, wherein the third module comprises interlocking means to interlock the third module with the first and or second modules.

15. Apparatus according to claim 13 or 14, wherein the third module comprises means for changing the angle of inclination of the inclined surface.

16. Apparatus according to any one of claims 13 to 15, wherein the third includes means for changing the height of the top surface.

17. Apparatus according to claim 9, wherein the first module includes both the top surface and the inclined surface.

18. Apparatus according to claim 17, wherein the first and second modules further comprise interlocking means to interlock the modules together to form the unit.

19. Apparatus according to any one of claims 9 to 18, wherein the first module and/or the second modules includes means for changing the height of the top surface.

20. Apparatus according to any one of claims 9 to 19, wherein at least one of the modules is adaptable to receive an insert, the insert providing means for the trainer to hurdle over the at least one module.

21. Apparatus according to claim 20, wherein the height of the insert is variable.

22. Apparatus according to claim 21, wherein the apparatus comprises a plurality of inserts, each insert having a different height such that the inserts are interchangeable to vary the height of the hurdle.

23. Apparatus according to anyone of the preceding claims, wherein at least a portion of the underside surface of the unit has a non-slip surface.

24. Apparatus according to claim 12 or 28, wherein the interlocking means comprises a slot in the upper surface of the second module and a complementary projection extending from the lower surface of the first module such that the projection of the first module sits within the slot of the second module.

25. Apparatus according to any one of claims 9 to 24, wherein the height of the first module is variable.

26. Apparatus according to claim 25, wherein the apparatus comprises a plurality of first modules, each first module having a different height such that the first module of the unit is interchangeable to vary the height of the unit.

27. Apparatus according to any one of claims 13 to 16, wherein the height of the third module is variable.

28. Apparatus according to claim 27, wherein the apparatus further comprises a plurality of third modules, each third module having a different height such that the third module of the unit is interchangeable to varying the height of the top surface above the ground.

29. Apparatus according to claim 14, wherein the interlocking means comprises a slot in the lower surface of the second module and a complementary projection extending from the upper surface of the third module such that the projection of the third module sits within the slot of the second module to form the unit.

30. Apparatus according to claim 13, 25, 26 or 29, wherein the upper surface of the third module is inclined such that, in use, the second module and/or first module rests on the inclined upper surface to provide a predetermined angle of inclination of the inclined surface.

31. Apparatus according to claim 30, wherein the angle of the inclined upper surface of the third module is variable.

32. Apparatus according to claim 31, wherein the apparatus comprises a plurality of third modules, each third module having different angles of inclination of its upper surface such that the third module of the unit is interchangeable to vary the angle of inclination of the inclined surface.

33. Apparatus according to claim 22, 24, 26 or 30, wherein the interchangeable modules and/or inserts include identification means for distinguishing the different modules or inserts.

34. Apparatus for plyometric training as hereinbefore described with reference to any one of figures 2 to 7b.