the portable multi - purpose whole body exercise device is designed for use by persons who want to perform general fitness , pilates - type , core strengthening , therapeutic , and rehabilitative exercises . some embodiments encompass less than portable features and are designed to be accompaniments for the home , studio or outdoor use . the basic unit is designed to be portable with extending attachments for easy setup and use . since there are a large range of human physiques , there is a need for larger size apparatus for individuals greater than 6 feet , 3 inches tall . the larger model would be longer in length and larger in diameter , but would have the same extension and attachment features as the basic device . additionally , a smaller model could be provided for use by persons of less than average size . the portable multi - purpose whole body exercise device can be utilized in different configurations depending upon which types of exercising or stretching is required . for example , fig1 is a perspective view of the portable multi - purpose whole body exercise device with extension bars in their stored position . the rigid core roller 11 is covered by a resilient covering 12 over the middle outer surface of the roller with the extents ( or extruded ends ) of the rigid portion 11 exposed . the resilient covering 12 is attached to the outer surface of core 11 , and can be changed out after extensive wear . each end of the rigid core 11 has notches 20 and holes 21 for receiving tension bands and extension bars . the portable multi - purpose whole body exercise device in this configuration can be utilized for general fitness , pilates , stretching and other exercises typical to a foam roller . a side perspective of the portable multi - purpose whole body exercise device with lateral extension bars 13 a and 13 b extracted on one end of the core roller 11 and nested in notches 20 is shown in fig2 . variable resistance modules ( vrm ) 15 a and 15 b are attached to extension bars 13 a and 13 b via the swivel bracket 14 a and 14 b . hand or foot loops 16 a and 16 b are connected to a pull cord inside the variable resistance module ( vrm ) 15 a and 15 b for resistance exercises . the variable resistance module ( vrm ) 15 a and 15 b can be configured to provide selectable incremental resistance in ranges of , for example , 3 , 6 , and 9 pounds of resistance , or for example , in ranges of 5 , 10 , and 15 pounds of resistance , or any other suitable incremental weight ranges . a side perspective of the portable multi - purpose whole body exercise device with both lateral extension bars 13 a and 13 b extracted and vertical extension bar 17 a placed in hole 21 a at one end of the rigid core roller 11 is shown in fig3 . resistance mechanism 15 c and 15 d are securely attached to vertical extension bar 17 a and can be used via hand or foot loops 16 c and 16 d for overhead strengthening exercises when the user is laying face up lengthwise on top of the core roller with head adjacent to vertical extension bar 17 a . the cylindrical shape of the portable multi - purpose whole body exercise device allows for advanced users to perform exercises with the variable resistance modules ( vrm ) while balancing on the core roller . for users that are less apt for that level of exercise , stabilization wedges 30 and 31 are provided . these are used to stabilize the roller while lying on the roller lengthwise and using the tension pulleys , a weight load mechanism or the variable resistance module ( vrm ) for strengthening exercises . the wedges can each be formed from a single rectangular block having a generally semi - circular cut out along a longitudinal side thereof to accommodate the circumference of the roller . alternatively , the wedges can be formed of two mirror image shaped pieces that when placed end to end have the same general configuration of the single block wedge . as shown in fig4 , the portable multi - purpose whole body exercise device includes lateral extension bars , 13 a , 13 b , 13 c , 13 d , and vertical extension bars , 17 a and 17 b in position at both ends of portable multi - purpose whole body exercise device . additionally , stabilization wedges 30 and 31 can be provided to prevent the roller from moving on the supporting surface . one of the truly unique features to this exemplary embodiment is the storability of the extension bars . fig5 is a perspective cross section view of the portable multi - purpose whole body exercise device showing extension bars 13 a and 13 b in their extracted position . extension bars 13 a and 13 b can slide within channels 40 a and 40 b , and can be secured to channel 40 a and 40 b by pins 42 a and 42 b . pins 42 a and 42 b slide in slots 41 a and 41 b respectively to secure extension bars within the core roller . fig6 and 7 are top cross section views showing extension bars 13 a and 13 b in partially extracted , and fully retracted positions without swivel brackets or tension pulleys , a weight load mechanism , or a variable resistance module ( vrm ) attached . fig8 shows the portable multi - purpose whole body exercise device with removable end caps 46 used for storage and transportation of the roller . fig9 shows the portable multi - purpose whole body exercise device in a carrying bag for easy transport . fig1 a - h show six types of exercise that can be performed on the portable multi - purpose whole body exercise device . for example , a triceps exercise is shown in fig1 b , an abdominal / oblique cross exercise is shown in fig1 c , a parallel toes exercise is shown in fig1 d , a seated row exercise is shown in fig1 e , a butterfly (“ pec fly ”) exercise is shown in fig1 f , a “ seated rotating swing ” exercise is shown in fig1 g , and a standing squat exercise is shown in fig1 h . the inventors envision numerous exercises that can be performed but are not shown here . for example , as listed in table 1 , various types of warm up exercises , stretches , sport specific exercises ( for example golf or tennis swing exercises ), and general fitness exercises can be performed . as can be seen from the exemplary exercises listed in table 1 , the numerous accessories , which can and do fit within the core of the roller to increase the portability of the exercise device , and the numerous configurations of exemplary embodiments of the portable exercise device provide an increased number of exercise options that can be performed using the exercise device , and thus add to the versatility of the basic device . other embodiments that have been envisioned by the inventors are also provided . one such embodiment is in fig1 a which includes extension bars that are stored loosely inside the core roller , removed and placed in holes at the end of the rigid core roller . tension bands may be secured to holes in the ends of the extension bars for resistance exercises . fig1 b shows extension bars with swivel brackets and variable resistance modules shown in various storage positions inside the core roller . another embodiment shown in fig1 is a stabilization board 32 with a hole cut out to receive one of the rigid end portions of the portable multi - purpose whole body exercise device , and can be used to assist in supplying additional stabilization of the roller during use . tension bands may be placed in holes 33 or secured around the back of the stabilization and engage with notches 34 on said stabilization board for additional resistance exercises . the shape of the stabilization board 32 in fig1 can vary to be rectangular or even circular with a flat edge that engages the floor during use . retaining pin 35 placed in hole 21 on the end of the rigid core would keep the stabilization board from sliding off the end of the rigid core roller 11 during use . another accessory is shown in fig1 and fig1 . a floor stand 36 may be employed to hold the portable multi - purpose whole body exercise device vertical for use with certain types of exercise or to simply store the exercise device while taking up less floor space . in another exemplary embodiment , fig1 a shows a perspective view of the swivel bracket 14 attached to the variable resistance module 15 , including the resistance changing knob . fig1 b shows a front , side & amp ; bottom view of the swivel bracket 14 attached to the variable resistance module 15 . an alternate embodiment of the portable multi - purpose whole body exercise device is shown in fig1 - 21 b . in this embodiment , which has substantially similar construction to previously described embodiments , a rigid core roller 50 having an interchangeable resilient covering 52 is provided . as seen in fig1 , the rigid core roller 50 has extruded ( open ) ends that extend beyond the ends of the resilient covering 52 in the longitudinal direction thereof . one open end of the rigid roller 50 can be closed by a dummy cap 54 that is not intended to be easily removed . the dummy cap 54 can be integrally formed with the roller 50 , or may be separately formed , and may be generally permanently attached to the open end of the roller , for example , by adhesive bonding or by rivets . the other open end 56 of the rigid roller 50 can be selectively closed by a removable and lockable cap 58 . the details of the removable and lockable cap 58 closing the open end of the roller 50 are shown in fig1 - 18 b , and will be further discussed below . a removable extension bar 64 is furnished for positioning at the open end 56 of the roller 50 so as to provide perpendicular extension arms that extend away from the body of the roller . a clevis 66 and variable resistance module ( vrm ) 68 are provided at respective ends of the extension bar 64 . a hand or foot loop 74 is connected to a cable or cord 76 that is wound within the variable resistance module ( vrm ) 68 , so as to provide resistance to a user &# 39 ; s hand or foot that grasps or is inserted into the hand or foot loop 74 . in this manner , the portable multi - purpose whole body exercise device can be used for any multitude of previously described exercises . as best seen in fig1 and 20 , the variable resistance module ( vrm ) 68 can rotate within the clevis 66 through almost 360 degrees , and is only limited in the angle of rotation by a rotation stopper portion 70 provided on the casing of the variable resistance module ( vrm ) 68 , which selectively engages the supporting arms of the clevis 66 to prevent complete , uninterrupted rotation of the variable resistance module ( vrm ) 68 . the rotation stopper portion 70 can be configured in a generally raised v - shape such that one side of the v - shaped rotation stopper 70 selectively engages one side of the arm of the clevis 66 to prevent rotation in one direction , and the other side of the v - shaped rotation stopper 70 selectively engages the other side of the arm of the clevis 66 to prevent rotation in the opposite direction . thus , the selective engagement of the v - shaped rotation stopper 70 with the arm of the clevis prevents rotation of the variable resistance module ( vrm ) 68 in a complete circle . as can be seen best in fig1 , the variable resistance module ( vrm ) 68 also include two resistance selection buttons 72 . as previously mentioned , the variable resistance module ( vrm ) 68 can provide three distinct incremented resistances . when neither of the two resistance selection buttons 72 are pressed in , a first , least amount of resistance is provided . when one of the two resistance selection buttons 72 is pressed in , a second , intermediate resistance is provided . a third , maximum resistance is provided when both of the resistance selection buttons 72 is pressed in . the variable resistance is accomplished by way of multiple spring resistance members provided within the variable resistance module ( vrm ) 68 , which selective ones of the multiple spring resistance members are engaged to resist rotation and unwinding of the cable or cord 76 when the different resistance selection buttons 72 are pressed in . the internal pulley that the cable or cord 76 is wound upon can be biased to automatically wind the cable or cord 76 when a pulling force applied by the user to the cable or cord 76 is released . the inner components of the variable resistance module ( vrm ) 68 are best shown in fig2 , 22 a , 22 b , 23 a , 23 b , 24 a , 24 b , and 25 . the resistance selection mechanism is the same for both resistance selection buttons 72 , and thus , the description below of one resistance selection button 72 is applicable to both resistance selection buttons 72 . in particular , in fig2 , 22 a , and 22 b , one resistance selection button 72 is shown in the pressed in configuration . the resistance selection button 72 includes a shaft 120 having a biasing member 122 received thereon , which shaft 120 passes through a shaft receiving cage 124 positioned within the variable resistance module ( vrm ) 68 . the end of the shaft 120 opposed to the resistance selection button 72 engages a pivot cam 126 . the pivot cam 126 engages a rocker bar 128 , which includes an engaging tooth 130 at one end thereof . as best exemplary shown in fig2 a and 24 b , each of the pivot cam 126 and the rocker bar 128 are biased to provide the necessary contact therebetween ( the pivot cam 126 is biased into contact with the end of the shaft 120 and the rocker bar 128 is biased into contact with the pivot cam 126 ). when the resistance selection button 72 is pressed in to select a resistance , the pivot cam 126 is pivoted , and the rocker bar 128 rotates , such that the engaging tooth 130 engages one of the ratchet teeth on ratchet plate 132 . the ratchet plate 132 is coupled to a torsion spring ( not shown ), which engages a spring plate 134 , which spring plate 134 is coupled to a winding pulley 136 , which may also include a torsion spring ( not shown ) to provide a first resistance and / or to provide the mechanism to wind up the cable / cord 76 . when the resistance selection button 72 is pressed in to select a resistance and the engaging tooth 130 of the rocker bar 128 engages a ratchet tooth on the ratchet plate 132 , the ratchet plate 132 no longer freely rotates within the variable resistance module ( vrm ) 68 , such that the torsion spring is thus engaged between the ratchet plate 132 and the spring plate 134 to provide additional resistance against pulling of the cable / cord 76 . as shown in fig2 a and 23 b , when the resistance selection button 72 is not pressed , the engaging tooth 130 of the rocker bar 128 does not engage the teeth of the ratchet plate 132 , such that the ratchet plate 132 can freely rotate so that the torsion spring is thus not engaged between the ratchet plate 132 and the spring plate 134 , and therefore , the resistance is provided by the torsion spring and the winding pulley 136 only . the resistance selection button 72 is shown in detail in fig2 . the resistance selection button 72 is configured such that pressing the button in once locks the button in the depressed configuration , and pressing the button a second time releases the button from the locked , depressed configuration . in this manner , the resistance of the variable resistance module ( vrm ) 68 can be set and locked in one of three settings depending upon whether one , two , or none of the resistance selection buttons 72 are locked in the depressed configuration . in order to provide a wider variety of strength training , interchangeable variable resistance modules ( vrm ) 68 having different resistance increments can be provided for attachment to the extension bar 64 . as shown in fig2 a and 26 b , the clevis 66 also provides rotation , about an axis perpendicular to the rotation axis of the variable resistance module ( vrm ) 68 . the clevis 66 can allow any amount of desired rotation or can be provided with a rotation limiting mechanism . for example , as shown in fig2 , a clevis 66 rotation limiting mechanism is provided . the exemplary rotation limiting mechanism is in the form of a groove 94 formed in the clevis rotation shaft 96 , which is inserted into the end of the extension bar 64 . the circumferential size of the groove 94 determines the amount of angular rotation of the clevis 66 . a stud 98 ( in this case a screw or machine screw ) is inserted through the extension bar 64 and sits within the groove 94 in order to limit rotation of the clevis 66 with respect to the extension bar 64 . any suitable and desired range of rotation , for example , 270 degrees , 180 degrees , 90 degrees , 45 degrees , or any other desired range within 360 degrees , can be provided by provided the groove 94 in the desired amount of rotation around the circumference of the clevis rotation shaft 96 . like previously discussed embodiments , the extension bar 64 is removable from the roller 50 , and can be stored within the hollow cavity of the roller 50 for ease with portability of the multi - purpose whole body exercise device . in order to easily repeat and properly position the extension bar 64 on the roller 50 , as shown in fig1 , locating notches 60 are provided in the wall of the roller 50 at the open end 56 thereof . while four locating notches 60 are shown , fewer or more can be utilized . the extension bar 64 includes locating flanges 78 that are complementary shaped and correspondingly positioned with respect to the locating notches 60 , so that the locating flanges 78 seat within the locating notches 60 to properly position the extension bar 64 . additionally , a positioning piece 80 can be provided to further ensure proper positioning and retention of the extension bar 64 . the positioning piece 80 also includes locating flanges 82 and can be inserted into the open end 56 of the roller 50 on top of and perpendicularly to the extension bar 64 , so that the locating flanges 82 engage with the locating notches 60 that are not engaged by the locating flanges 78 of the extension bar 64 . further , the removable and lockable end cap 58 is attached to the open end 56 of the roller 50 to lock the extension bar 64 and positioning piece 80 in place . as seen in fig1 , lock stops 62 are positioned around the inner circumferential surface of the open end 56 of the roller 50 for selective engagement with lock stop receiving portions 86 on the removable and lockable end cap 58 ( fig1 a , 18 b ). the removable and lockable end cap 58 is provided with a handle 84 so that a user can grasp the handle 84 to insert the end cap 58 into the open end 56 of the roller 50 and rotate the end cap 58 from an unlocked orientation to a locked orientation . the handle 84 includes a biased lock button 88 , which , as shown in fig1 a and 18 b , includes a ramped portion 90 having a locking edge 92 at one side thereof to selectively engage a lock stop 62 in order to prevent accidental rotation of the end cap 58 to an unlocked orientation . in use , the end cap 58 is inserted into the open end 56 of the roller 50 with the lock stops 62 aligned for insertion into a respective lock stop receiving portion 86 . the end cap 58 can then be rotated without engaging the lock button 88 , such that the lock stop 62 comes into contact with the ramped portion 90 of the lock button 88 to cause the lock button 88 to move against the biasing force to allow the lock stop 62 to move past the lock button 88 into the lock stop receiving portion 86 . once the lock stop 62 has moved past the lock button 88 and into the lock stop receiving portion 86 , the lock button 88 is biased back into the unactuated position , such that the locking edge 92 engages and prevents the lock stop 62 from rotating out of the lock stop receiving portion 86 . in order to remove the end cap 58 , the lock button 88 is actuated against the biasing force so that the locking edge 92 no longer engages the lock stop 62 , such that the lock stop 62 can be rotated out of the lock stop receiving portion 86 . in this manner , the removable end cap 58 is selectively lockable to prevent the accidental rotation thereof in order to securely retain the extension bar 64 connected to the open end 56 of the roller 50 . it can be seen that this embodiment of the portable multi - purpose whole body exercise device therefore provides a quick and easy method of configuring the device from a portable configuration , where the extension bar is stored within the device , to an operative configuration , where the extension bar is positioned at the end of the device to provide resistance modules to aid with providing numerous different exercises for a user to perform . various accessories for the portable multi - purpose whole body exercise device can also be provided . for example , as shown in fig2 for users who may have weaker pelvic and hip bones , such as elderly users or persons having osteoporosis , additional protective accessories may be provided . in particular , a cushioned pad 100 , which may be of any suitable shape or size , and which may be formed from a suitable viscoelastic foam or gel material , such as , for example , silicone , or may include an inflatable bladder , can be provided to lay flat across the roller under the pelvic region of the user during specific exercises that require the user to lie or sit on the roller . in this way , the cushioned pad 100 provides additional support to the pelvic region of the user . an alternative accessory , as shown in fig2 , which can also be provided for users who may have weaker pelvic and hip bones , or for larger sized users , is a stability box 102 . the stability box 102 is in the form of an elongated box that is placed over the roller so that a user can lie or sit on the stability box 102 , instead of the roller 50 , in order to perform specific exercises . the stability box 102 can open at the longitudinally opposed ends thereof to accommodate the roller 50 within the stability box 102 , so that one or both of the ends of the roller 50 can extend beyond the ends of the stability box 102 . in this way , the stability box 102 can provide a more stable , as well as a larger surface area for the user to lie or sit upon while performing specific exercises , yet still allowing for some level of user interface with the roller itself in order to maintain the instability element of certain exercises . a similar accessory to the stability box 102 may be provided , as shown in fig3 , to provide the roller with a configuration suitable for use as a step exercise device . in particular , stability steps 104 can be provided to sit over the extension bars 64 ( like the stability box 102 covers the roller 50 ), and to provide support underneath the extension bars 64 to prevent rotation of the roller 50 on the supporting surface . with the stability steps 104 in place over and supporting the extension bars 64 , a user can perform step exercises , with or without manipulating the hand loops 74 to utilize the variable resistance modules ( vrm ) 68 . as shown in fig3 and 32 , an additional accessory may be a vertical extension bar 106 ( the general details of which are described above with respect to extension bar 64 ), which can be removably connected to the removable end cap 58 , for example , by inserting one end of the vertical extension bar 106 into a hole provided in the removable end cap 58 . any other suitable mechanism for removably connecting the vertical extension bar 106 to the removable end cap 58 may also be used . as shown , the vertical extension bar 106 can include two variable resistance modules ( vrm ) 68 connected to the opposed end thereof . in the exemplary embodiment shown in fig3 , the vertical extension bar 106 is provided with a clearance curvature 108 near the removable end cap 58 in order to provide more clearance between the user and the vertical extension bar 106 . like the extension bar 64 , the vertical extension bar 106 can be configured to be retained within the center of the hollow portion of the roller 50 for ease of transportation . the use of a further accessory is shown in fig3 a and 33 b . in particular , an inner case 110 is provided to accommodate and protect the extension bar 64 when the extension bar is stored inside the roller 50 . the inner case 110 can be formed in a generally cylindrical configuration and having closed ends , with an opening 112 provided generally longitudinally along one side thereof . the extension bar 64 can be inserted through the opening 112 into the case 110 . the inner case 110 can be formed from any suitable material , and may be a semi - rigid or soft case . exemplary materials include , for example , soft fabrics , neoprene rubber , any other open or closed cell foam or any gel material , or any suitable plastic material , such as , for example , low or high density polyethylene . if the case 110 is made from a fabric material , the opening may be closed by , for example , the use of a zipper closure , snap closures , and / or hook and loop closures . for a semi - rigid plastic case , the inherent resiliency of the material will tend to close the opening . once the extension bar 64 is inserted through the opening 112 and into the case 110 , the case 110 can be inserted into the open space of the roller 50 , as shown in fig3 b for storage and to ease portability of the exercise device . additional accessories which may be provided include , but are not limited to , an exterior carrying bag ( for example , as shown in fig9 ) provided to enclose the exercise device therein for ease of transporting the exercise device . such a carrying bag can include one or more straps , for example , shoulder straps , so that the exercise device may be more easily carried in a hands free manner . such a shoulder strap may be provided , for example , directly removably attached to the ends of the exercise device itself , for example by snap fasteners , or by clips at the ends of the strap , which removably connect to rings secured at the ends of the exercise device . it will be recognized that the portable multi - purpose whole body exercise device and components thereof can be made from any suitable materials . it will also be recognized that , while specific size ranges for components of the portable multi - purpose whole body exercise device have been disclosed , the portable multi - purpose whole body exercise device and components thereof may have any suitable size as may be appropriate for use by persons having different sizes . of course , it is to be understood that not necessarily all objects or advantages may be achieved in accordance with any particular embodiment of the invention . thus , for example , those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein . the skilled trainer or athlete will recognize the interchangeability of various disclosed features from the disclosed embodiments and variations . in addition to variations described herein , other known equivalents for each feature can be mixed and matched by one of ordinary skill in this art to construct a portable multi - purpose whole body exercise device in accordance with principles of the present invention . although this invention has been disclosed in the context of exemplary embodiments and examples , it therefore will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses of the invention and obvious modifications and equivalents thereof . thus , it is intended that the scope of the present invention herein disclosed should not be limited only to the particular disclosed embodiments described above .