Abstract: An exercise apparatus includes a compact resistance unit that houses a pneumatic cylinder. The cylinder is connected to a pulley wheel that moves at least toward the cylinder. A main cable extends about a portion of the pulley wheel. One end of the main cable is fixed to the unit housing and the other end is attached to a pulley block of a block-and-tackle mechanism. A user cable extends through the block-and-tackle mechanism and is connected to a handle. The pneumatic cylinder resists movement of the handle away from the unit.

Abstract: An improved rock climbing simulator that uses an adjustable fluid resistance apparatus coupled to an axle of a rotating climbing surface to control the rate of rotation of the climbing surface and thus the perceived climbing speed experienced by the climber. The fluid resistance apparatus is structured to control the rate of rotation of the climbing surface, and hence the perceived climbing speed, regardless of the weight or position of a climber on the climbing surface.

Abstract: A device for increasing the range of motion of a patient's knee joint generally includes a frame, a lever member pivotally coupled to the frame at a first location, and an actuator pivotally coupled to the frame at a second location. The frame supports the patient in a manner that allows motion of the patient's knee joint, and the lever member bears against a portion of the patient's body below the knee joint. The actuator is also pivotally coupled to the lever member. When operated by a controller, the actuator generates a translational input that rotates the lever member relative to the frame and thereby stretches the patient's knee joint in a desired direction.

Abstract: An exercise apparatus includes a compact resistance unit that houses a pneumatic cylinder. The cylinder is connected to a pulley wheel that moves at least toward the cylinder. A main cable extends about a portion of the pulley wheel. One end of the main cable is fixed to the unit housing and the other end is attached to a pulley block of a block-and-tackle mechanism. A user cable extends through the block-and-tackle mechanism and is connected to a handle. The pneumatic cylinder resists movement of the handle away from the unit.

Abstract: An apparatus and control system for establishing and maintaining a user selected magnitude and direction of pneumatic resistance provided by exercise equipment includes at least one electrically controlled regulator for admitting air to and releasing air from the pneumatic system, transducer for measuring air pressure within the system and providing a corresponding signal, potentiometer for setting and monitoring system pressure in response to signal input from the transducer, air accumulator tank, and pneumatic piston cylinder assembly. The apparatus may also include at least one user controlled electrically switchable four way valve for providing bi-directional resistance. The apparatus is adaptable for providing unilateral or bilateral exercise movements, with or without bi-directional resistance, and can be used to provide range of motion exercise without resistance.

Abstract: An apparatus for physical fitness physical strength, agility and endurance training. A controllable pressurized flow of fluid is first received via a hose to a source of the pressurized fluid. In response to this flow of fluid, a force is generated along at least one of a plurality of selected directions using one or more apertures or nozzles. The force is then transferred to a user of the apparatus so as to supply physical resistance training to the user. The apparatus further includes a user engaging mechanism that is connected to the propulsion system, and is configured to transmit exercise forces to an associated user. The apparatus further includes controls for controlling the magnitude and direction of the reaction force vector applied to the user engaging mechanism. Various embodiments of user engaging members, including blocking dummies, handles, gloves, helmets, shoes, straps or balls, may be attached to the propulsion system.

Abstract: A variable resistance device is adapted to be incorporated in an exercise machine to provide variable resistance. The device has a primary fluid chamber. A rotating mechanism rotates within the primary chamber. The rotation mechanism upon rotation encounters a degree of resistance dependent on the amount of fluid in the primary chamber. A secondary chamber is positioned within or proximate the primary chamber. The secondary chamber achieves and maintains an appropriate amount of the fluid in the primary chamber to provide a selected degree of resistance for the exercise machine. Fluid flows through the primary chamber into the secondary chamber and then back into the primary chamber. Variable control of the flow of fluid serves to establish and maintain the appropriate amount of fluid in the primary chamber required for a certain degree of resistance; and can provide differing degrees of resistance for the exercise machine.

Abstract: A swing rotary fitness apparatus is described. A swing base is axially disposed at a center of a bracket having a pair of handles. A pound-force adjuster is disposed between the swing base and the bracket, and elastic elements for restoration are disposed between the swing base and the bracket. In addition, a rotatable seat is disposed on the swing base. When a user rides on the seat, the user exerts a force by lumbar muscles, so as to generate a circumferential motion of synchronous swing and rotation, which increases amplitude of twisting lumbar muscles greatly and thus improves an effect of exercising the waist.

Abstract: An air spring is used as a resistance device in exercise equipment having a lever arm for exercising various muscle groups such as those in arms and legs. In one embodiment, the equipment can be used while standing and the resistance movements strengthen core muscles. In another, it can be adapted to be used on a table surface for exercising hands, wrists and forearms. In still another embodiment, it can incorporate a bike pedal assembly to simultaneously aerobically exercise the legs and arms. The equipment includes resistance level regulating components and a visual indicator using a gauge or similar device to monitor resistance levels. Embodiments also include interchangeability of human interface members and a hand pump integrated with the lever arm, which may also include interchangeability of the human interface members.

Abstract: An exercise apparatus includes a housing, a pair of pivoting foot treadles and a pair of reciprocating bellows that support the foot treadles. A sealed air system including a conduit interconnects the bellows and is operable for reciprocating transfer of air from bellow to bellow. Each of the foot treadles is pivotably movable between upper and lower positions, and has a resting position between the upper and lower positions. The resting position of the foot treadles defines a resting position of the bellows while the upper and lower positions of the foot treadles respectively define elongated and compressed positions of the bellows. In use, the elongated and compressed positions of the bellows are each no more than 5 degrees off the center resting position thereby reducing stress on the bellows.

Abstract: A foot and/or leg-exercising device (10) has a first sealed chamber (14) and a second sealed chamber (16) that are interconnected via one or more passageways (34). The chambers (14, 16) are of variable volume and fluid within one chamber may be pumped to the other chamber using the feet and/or legs. In one embodiment each foot is provided with a first chamber and a second chamber and fluid is pumped by a heel and toe rocking action of each foot. The chambers for both feet may be interconnected to allow pumping by an up and down action of the legs.

Abstract: An apparatus for exercising the abdominal muscles of a user includes an elongate track having first and second ends and a middle portion wherein the elongate track is positionable transverse to a user. The apparatus further includes a carriage movable along the track, wherein that carriage is biased toward the middle portion of the track, and an arm extending substantially perpendicular from the carriage. The arm has a free distal end such that application by user of an alternating torque to the free distal end of the arm urges the carriage in a corresponding reciprocating motion on the track.

Abstract: A free-weight bench (10) is provided having a safety assist device (12) for preventing injury to a weight lifter who repetitively lifts a barbell weight (16) including a weight bar (42). The safety assist device (12) includes a pair of spaced apart arms (32,34) oriented to permit the bar (42) to move along the length thereof, and a bar-sensing apparatus (45) comprising a plurality of sensors (46) on the arms (32,34) as well as a processor (60) programmed to determine at least one parameter related to the velocity of the bar (42) as it moves along the arms (32,34). Respective extensible supports (47) comprising fluid-actuated piston and cylinder assemblies (48,50) are located adjacent corresponding arms (32,34) and are controlled by the processor (60).

Abstract: This patent discloses a machine to assist a person in strength training. The strength training machine may have a bar supported between two uprights. A motor and mechanisms may cause the bar to move up and down at a constant rate. A person may position themselves above, below, or to a side of the bar. As the bar moves, a person may push or pull against the resistance provided by the moving bar. The motor and mechanisms may prevent the bar from moving in response to the person pressing or pulling against the bar, no matter how hard the person presses or pulls on the bar.

Abstract: An exercise apparatus has a table having a pair of opposed longitudinal edges, front and rear support elements for supporting the table above the ground, a pair of base elements, and a pair of exercise arms. Each of the pair of exercise arms is pivotally connected to a mounting point of one of the pair of base elements, and includes a vertical arm, a rotational connector rotatably connecting the vertical arm and the pivot element, a horizontal arm pivotally connected to the vertical arm, and a resistance device operably connected between the vertical and horizontal arms to provide resistance when the horizontal arm is moved with respect to the vertical arm.

Abstract: A control system is provided for an exercise machine. The control system varies the resistance of the exercise machine. The control system varies the resistance based on voice commands, based on commands programmed by the user, and based on how the user performs an exercise. The exercise machine can include a pneumatic system that can produce constant or variable resistance during on exercise, can include cable exercises, can include exercises utilizing a cam, and can include a cam that can be moved between different operative positions.

Abstract: An exercise device has two identical, parallel, solid, metal bars connected by an adjustable resistance hydraulic cylinder. The hydraulic cylinder is attached to the lower metal bar while the piston is connected to the upper metal bar. Oversized, cushioned grips are attached to both the upper and lower metal bars for comfort and increased gripping ability. A multi-staged resistance adjustment device is located on the upper end of the hydraulic cylinder. The oil or air filled hydraulic cylinder provides resistance in both the push and pull motions. Various body positions are facilitated to target specific muscle groups. Exercises include abdominal crunches, bicep curls, triceps presses, chest flies, upright rows and leg squats.

Abstract: An improved method and apparatus for physical strength, agility and endurance training uses fluid jet reaction forces to train and strengthen muscles. The device for physical training includes a source of pressurized fluid connectable through a hose to a propulsion system and one or more apertures or nozzles for forming one or more jets of fluid that are discharged from the propulsion system such that a nozzle reaction force, acting in a direction opposite the direction of the jet stream, is exerted on the jet propulsion system. Fluid can also be delivered through a curved tube or passage in the propulsion system such that a stream of fluid that is discharged from the propulsion system is not traveling in the same direction as it was before it was discharged such that the change in direction of the fluid causes a change in the momentum of the fluid for exerting an additional reaction force on the propulsion system.

Abstract: An exercise device includes first and second housings telescopically coupled together. A pneumatic cylinder is positioned inside and fixed to the first housing and includes proximal and distal ends. A piston having a piston head and shaft is situated inside the second housing, the piston head separating an interior space of the cylinder into first and second areas. Telescopic movement of the housings causes the piston head to move within the interior space. A first check valve is in fluid communication with the cylinder for adjusting an amount of resistance encountered by the piston head as it travels toward the cylinder distal end. A second check valve is in communication with the cylinder for adjusting an amount of resistance encountered as the piston head travels toward the cylinder proximal end. Pneumatic and check valve communication channels are inside the housing. The device is adaptable to exercise multiple muscle groups.

Abstract: An orthotic apparatus for use in providing improved range of motion is provided which allows the amount of stretch to be hydraulically powered and measured by the device, but controlled by the user. Because the apparatus accurately calculates the amount of stretch, the user, together with the user's physician and therapist, can develop a rehabilitation plan based on accurate measurements. Progress is based on tangible results rather than the user's ability to tolerate pain. This knowledge provides the incentive the user needs to work toward and achieve the user's goal.

Abstract: An exercise machine including a frame and a drive arm pivotedly engaged to the frame, for example, on an upright thereof. A cylinder is mounted at one point to the frame and, at a removed end of a plunger, has links or rod members to engage the removed end of the plunger to the frame and also to the drive arm.

Abstract: The present invention describes a specialized exercise apparatus and method for use that targets the muscles in and around the abdominal, oblique muscles and mid section of the body. The machine is comprised of a flat platform upon which an individual stands while grasping a pair of handlebars that are positioned at waist height. The handle bars are attached to the top of a vertical riser that extends downwardly and is attached to a pair of horizontal rotating pivot arms. The vertical riser is additionally comprised of a resistance mechanism that allows for compression of the vertical riser in a downward movement. The pivot arms are attached to the center of a rotating power pulley horizontally suspended by bearings below the forward area of said platform. The power pulley is connected by a belt to a resistance mechanism.

Abstract: Provided herein is an innovative human powered pumping device comprising a piston and cylinder pumping mechanism that is hinged off a base. In use, the piston is driven in and out of the cylinder by a handle which is pushed and pulled by the operator. The base is resting on the ground and the cylinder is hinged off the base such that the pumping mechanism can rotate with respect to the base during the pumping motion.

Abstract: A device for increasing the range of motion of a patient's knee joint generally includes a frame, a lever member pivotally coupled to the frame at a first location, and an actuator pivotally coupled to the frame at a second location. The frame supports the patient in a manner that allows motion of the patient's knee joint, and the lever member bears against a portion of the patient's body below the knee joint. The actuator is also pivotally coupled to the lever member. When operated by a controller, the actuator generates a translational input that rotates the lever member relative to the frame and thereby stretches the patient's knee joint in a desired direction.

Abstract: The invention relates to an exercise apparatus comprising an arm arrangement and resistance means. The arm arrangement comprises an arm (2) mounted on a carriage (4, 40), which carriage (4, 40) is mounted on guidance means (5, 8) for translational movement along a path. The resistance means is arranged to resist movement of the arm (2) relative to the carriage so that, in use, a user can move the arm (2) relative to the carriage (4,40) in order to work against the resistance means. The guidance means is a linear guidance means for guiding the carriage (4,40) along a substantially linear path. In use, the carriage (4,40) is moveable, guided by the guidance means, in two directions as the user works against the resistance means, said movement of the carriage (4,40) is substantially unresisted.

Abstract: An exercising device includes flexible main body comprising a leg engaging portion and a torso engaging portion. A flexible gas filled bladder is attached to the flexible main body wherein when an exerciser flexes the main body and compresses the gas within the bladder, the targeted muscles are exercised.

Abstract: A resistance assembly for a hydraulic resistance exercise apparatus includes a single-action hydraulic cylinder having a longitudinal axis and extending from a first end to a second end. The single-action cylinder provides resistance to compression of the cylinder, one end toward the other, but provides little or no resistance to extension of the cylinder, one end away from the other. A first compression linkage compresses the hydraulic cylinder in response to movement of a first exercise resistance lever in a first direction. A second compression linkage compresses the hydraulic cylinder in response to movement of a second exercise resistance lever in a second direction directly opposed to the first direction. An engagement exercise lever includes an engagement pin for selectively engaging the engagement exercise lever to move in fixed relation to one or the other the first or second exercise levers in both the first and second direction.

Abstract: An exercise machine, more specifically, an abdominal exercise machine. The abdominal exercise machine consists of a frame upon which the user sits, the frame having a support arm tilted backward from vertical with the lower lumbar region against a seat member. Pivotally attached to the frame is an upper seat rest assembly that has a pair of handles and a pad designed to lay against the upper back of the user. The seat back assembly moves with the upper body of the user, the hands of the user assisting in maintaining the upper seat back member against the upper back, while the user moves from a tilted back position to a crunch position, and simulating a traditional sit-up movement.

Abstract: A system is provided by applying pressure to a portion of a body of an individual in a chamber having an aperture along a vertical axis for receiving the portion of the body of the individual. A pressure sensor is coupled to the chamber for measuring a pressure inside the chamber. A negative feedback control system, calibrates, adjusts and maintains the pressure inside the chamber.

Abstract: A control system is provided for an exercise machine. The control system varies the resistance of the exercise machine. The control system varies the resistance based on voice commands, based on commands programmed by the user, and based on how the user performs an exercise. The exercise machine can include a pneumatic system that can produce constant or variable resistance during on exercise, can include cable exercises, can include exercises utilizing a cam, and can include a cam that can be moved between different operative positions.

Abstract: The present invention relates to an exercise device, which includes a vacuum cylinder and a flywheel. The flywheel provides an inertial component to the load, which is particularly well suited for use in space as it simulates exercising under normal gravity conditions. Also, the present invention relates to an exercise device, which has a vacuum cylinder and a load adjusting armbase assembly.

Abstract: The present invention relates to a pogo stick structure, more particularly, a pogo stick comprising a housing unit, foot support plate, piston, spring mechanism, and handlebars. The external portion of the housing unit includes a plurality of LED lights that light in accordance with the piston impinging the ground. LED lights displayed on the housing may be of different colors and may be arranged in a multitude of ways. Furthermore, the displayed LED lights may light in different patterns and at different times as a result of an electronic processing unit. A foam layer may cover the housing and protect the lights from accidental damage. The foam layer and lights may also be used with other entertainment devices such as stick horses.

Abstract: An exercise device comprising a chair attachment assembly adapted for attachment to a chair at a location under a seat of the chair and configured to extend outwardly therefrom. A pair of leg supports are pivotally coupled at first ends thereof to a pivot point on the chair attachment assembly. Each leg support is independently moveable between a contracted position and an extended position. A leg holder is coupled to each leg support near a second end thereof. A resistance element is pivotally coupled between each leg support and the chair attachment assembly. Each resistance element is configured to provide resistance against both outward movement of the associated leg support from the contracted position to the extended position and inward movement of the associated leg support from the extended position to the contracted position.

Abstract: A control system is provided for an exercise machine. The control system varies the resistance of the exercise machine. The control system varies the resistance based on voice commands, based on commands programmed by the user, and based on how the user performs an exercise. The exercise machine can include a pneumatic system that can produce constant or variable resistance during on exercise, can include cable exercises, can include exercises utilizing a cam, and can include a cam that can be moved between different operative positions.

Abstract: Exercise apparatus has a pair of members exercising a pair of limbs of a user to alternate between and first and second opposite direction motions, such as a stepper or stair climber, and is provided with a resistance mechanism coupled to the pair of members and having first and second modes resisting motion, with the first mode resisting a first member moving in a first direction, and the second mode resisting the second member moving in the first direction.

Abstract: The multifunctional portable pneumatic exercise device is a muscular exercise and training device that may be used for a multiplicity of exercises and with a wide variety of muscle groups. The exercise device includes a telescopic tube that is sealed at a distal end thereof and has a valve mounted on the proximal end thereof. In operation, the user compresses the telescopic tube and the increased air pressure within the telescopic tube causes fluid resistance, providing the user with muscular exercise. The user controls the fluid resistance through selective adjustment of the valve, which controls the volume of air escaping from the telescopic tube. Further, a pair of straps are releasably secured to either end of the telescopic tube, allowing the telescopic tube to be secured to a selected body part. The exercise device is portable, easy to operate and provides a wide range of muscular exercises for the user.

Abstract: The present invention relates to a pogo stick structure, more particularly, a pogo stick comprising a housing unit, foot support plate, piston, spring mechanism, and handlebars. The external portion of the housing unit includes a plurality of LED lights that light in accordance with the piston impinging the ground. LED lights displayed on the housing may be of different colors and may be arranged in a multitude of ways. Furthermore, the displayed LED lights may light in different patterns and at different times as a result of an electronic processing unit. A foam layer may cover the housing and protect the lights from accidental damage.

Abstract: An exercise machine for providing a motion, climbing a hill with hand weights, includes single swing arms with fixed foot platforms and forwardly extending substantially horizontal handles. The swing arms and foot platforms are interlocked through a flexible link and pulley arrangement. The machine has provision for adjusting the length of the travel arcs, which changes length of stride of the foot platforms, and the climbing effect, which alters the workout intensity. The machine of the invention is readily foldable for storage.

Abstract: A maximum muscle strengthening resistance device provides a way of exercise that allows the exercising person to exert his/her full power throughout the whole time of exercise. When a volume of fluid is forced to pass through a small opening, it produces a resisting force. This invention uses this resistive force produced by the oil flow along with the mechanical force generated by a power unit such as a hydraulic pump or an electric power motor for the resisting force during the strengthening exercises. Most of the muscle strengthening exercise is consisted of consecutive concentric-eccentric exercise cycles. By using this invention, during the concentric exercise cycle the exercising person actively exert his/her full power to move the exercising handle toward the concentric direction against above mentioned resistive force of oil flow.

Abstract: A portable exercising apparatus includes a first frame member, a second frame member, a first tube perpendicularly and fixedly connected to the first frame member, a second tube perpendicularly and fixedly connected to the second frame member and slidably inserted into the first tube and defining with the first tube an air chamber, an air valve mounted in the first tube in communication with the air chamber and the atmosphere, and two elastic members connected between the first frame member and the second frame member at two sides of the first tube and the second tube.

Abstract: A combination horizontal and vertical rope-pulling device that uses a hydraulic braking assembly that is mounted on a vertical frame to support an endless rope that is placed over a number of pulleys. A pivoting boom is attached at the top of the frame. In the vertical mode, the rotating boom is positioned at an angle extending rearward from the vertical frame. The rope passes over a number of pulleys to simulate a vertical rope for climbing. In the horizontal mode, the rotating boom is rotated down so that it is parallel to the vertical frame. The rope follows the downward run of the boom and around the pulleys. In this way, the user can use the machine as a horizontal rope-pulling machine.

Abstract: The present invention relates to a low-impact, time-efficient way to exercise both the cardio-respiratory system and the muscular system, particularly the abdominal and back muscles. The exerciser uses his muscles to oscillate a pivoted carriage within a frame. In one embodiment, the exerciser pedals a crank to pump hydraulic fluid through a hydraulic circuit to a hydraulic cylinder connected between the carriage and the frame so as to urge the carriage to oscillate with respect to the frame. A limit sensor detects when the carriage is positioned at one extreme of its oscillation and signals the hydraulic circuit to reverse the flow of hydraulic fluid to the hydraulic cylinder.

Abstract: An apparatus for exercising and supporting an upper limb includes two support modules connected on the first side by a rigid connecting piece. Both support modules have a frame, with a support plate fixed to their upper part. An exercising part is removably attached to the support plate of the first support module. An upper arm support part is articulated in the support plate and an actuator actuates the support part relative to the support plate. The frames of the support modules can be fitted immediately underneath the shoulder joints, the other upper limb being supported on the support plate in such a way that the upper limb exerts a force on the rigid connecting piece. The first upper limb is supported on the exercising part so that the weight of the upper limb exerts a force on the rigid connecting piece, the forces being balanced by the connecting piece.

Abstract: A muscle training device includes a base seat, a first support arm connected pivotally to the base seat, a second support arm connected pivotally to an impeding unit, and two supporting cushions connected respectively to the support arms. The impeding unit has a housing fixed to the first support arm, a piston unit, first and second fluid chambers formed on two opposite sides of the piston unit, a fluid filled in the first and second fluid chambers, and a passage unit that is in fluid communication with the first and second fluid chambers. The second support arm is turnable toward or away from the first support arm.

Abstract: The multifunctional portable pneumatic exercise device is a muscular exercise and training device that may be used for a multiplicity of exercises and with a wide variety of muscle groups. The exercise device includes a telescopic tube that is sealed at a distal end thereof and has a valve mounted on the proximal end thereof. In operation, the user compresses the telescopic tube and the increased air pressure within the telescopic tube causes fluid resistance, providing the user with muscular exercise. The user controls the fluid resistance through selective adjustment of the valve, which controls the volume of air escaping from the telescopic tube. Further, a pair of straps are releasably secured to either end of the telescopic tube, allowing the telescopic tube to be secured to a selected body part. The exercise device is portable, easy to operate and provides a wide range of muscular exercises for the user.

Abstract: An exercise machine which includes an elongate frame which forms an enclosure, a resistance assembly located at least partly in the enclosure, a support member for supporting the frame at an inclined position with an upwardly facing front side and a downwardly facing rear side, a seat extending from the front side of the frame at a location at which part of the frame opposes a back of a user seated on the seat, and at least a first actuator which is movable by the user against a first resistance force which is generated by the resistance assembly.

Abstract: Disclosed herein is a novel therapy cushion for use in conjunction with a conventional blood pressure cuff. The cuff is inserted into the cushion, and the cushion with inserted cuff is placed between the legs (or against one leg). The cuff is inflated and used as calibrated resistance training device for therapeutic/rehabilitation purposes. The device is especially effective following hip or knee replacement surgery. The manometer (on the blood pressure cuff) serves to indicate resistance level. Other variations are possible for other exercises.

Abstract: A chest exerciser includes an elongated plunger housing and a pair of plungers that move in sealed sliding contact with the plunger housing on opposite sides of a common air volume within said plunger housing. An adjustable vent, centrally located between the plungers, communicates with the common air volume. Each plunger is attached to a hand grip. The handles slide on and are coaxial with the plunger housing. In the fully retracted position the grip distance between the proximal end of said first plunger hand grip member and the proximal end of said second plunger hand grip member is between 0 and 10 inches. The exerciser is used in combination with a breast enhancement nutrient, such as pueraria mirifica, which may be applied to the breast as a cream or tonic or ingested as an herb or pill.

Abstract: A device is provided for exercising the muscles of the back, which includes a chair seat and a rod fastened to a feet plate. The feet plate is coupled to a tilting member which is surrounded by a damping member. The damping member can rest on a bottom plate which is fastened by a fastening member. A cloth which surrounds the damping member and is fastened to the feet plate can replace the bottom plate and the fastening member. It is further an advantage that the rod is telescopic. The tilting member can have a circular cross section and a downwardly conical form. The damping member which surrounds the tilting member is of a flexible material and may be fastened to the feet plate by the fastening means member which can assist in dampening the movement of the tilting member.

Abstract: The invention relates to a controllable load apparatus for use in machines for resistive exercise training of the human body. The apparatus comprises a pneumatic cylinder (10) having a piston (12) acting on a fluid and a piston rod (14), the piston/cylinder unit (10, 12) being operated on by a person undergoing training. A pressure accumulator (20) is connected to, and pressurizes the piston/cylinder unit (10, 12) at a predetermined pressure during exercise via a pneumatic control circuit (42). Once a predetermined pressure threshold is reached, a valve means operates to prevent further fluid being available for charging the accumulator (20).