This invention relates to exercise equipment, in particular to devices, apparatus, systems and methods for a portable, convertible and multifunction exercise apparatus that allows individuals to accomplish their fitness, health conditioning, weight loss and rehabilitation goals with a single multipurpose device. 
   BACKGROUND AND PRIOR ART 
   To date there are many commercially successful exercise devices, apparatuses, and machines to allow individuals to attempt to accomplish their fitness, health, conditioning, weight loss and rehabilitation goals, that are particularly related to aerobic steppers, platforms, resistance band tubing, and multipurpose equipment. While these apparatuses are adequate for their intended use, used separately these devices have limitations, drawbacks and deficiencies in both the number of exercises that can be performed as well as the muscle groups that may be exercised. A discussion of these types of devices will now be described. 
   Resistance Exercise Bands 
   Stand-alone elastic resistance bands are currently in mass use in the fitness industry, and are inexpensive, widely known and are used for improved strength, speed, power, and rehabilitation. They are a medically preferred method of training because they avoid undue stress on the joints and connective tissues, the user is free to explore a full range of fluid movement and receive the benefits of positive and negative resistance. Resistance bands or tubing of prior art are currently used alone or attached to a certain anchor point. i.e.: door, platform or housing. 
   A main disadvantage of resistance bands or tubing of has been the adjustability factor. To change the resistance level the user must separately change the thickness, length and/or connectivity of the tubing, thus causing inconvenience to the user and restricting the diversity of exercises which may be accomplished due to the variables of height, or strength levels and/or length requirements due to the starting point of the exercise. Another disadvantage is the lifespan of such bands, which must be replaced over time. 
   Aerobic Steps, Platforms, Benches 
   These types of devices are generally adjustable in height and are mainly used for cardiovascular and lower extremity conditioning, mostly used in class settings. However, with these systems the participant must generally buy and use a separate set of resistance bands or weights to accomplish the necessary degree of intensity required for a limited muscular workout. 
   U.S. Pat. No. 5,158,512 to Irwin et al. describe an adjustable stepping apparatus marketed worldwide under the name “THE STEP” as an aerobic unit which is height adjustable, and is used mainly for a cardiovascular workout. This device has limited capabilities of varied exercises and does not teach for conversion into a chair or bench. The Irwin device has no teachings and descriptions for attaching resistance bands/tubes and/or weights to the unit. Such weights and/or resistance bands-tubes would not be adjustable and would have to be purchased separately, used separately and stored separately from the Irwin unit. 
   U.S. Pat. No. 7,044,901 to Weir describes a multi configurable exercise station marketed worldwide under the name (THE DECK). This unit converts from a step to a bench, then a chair, it teaches for storage space. However the Weir device does not teach or describe anyway of attaching fixed adjustable resistance elements such as bands/tubes directly to the unit. Such weights and/or resistance bands-tubes would have to be purchased and used separately from the Weir station. 
   Multipurpose Equipment 
   These types of machines and apparatus have generally combined several taught disciplines including steps, weights and/or bars, resistance bands, attachments and benches combined, and have tried to fit the bill of an all in one unit. However, the prior art falls short when it comes to portability, adjustability, functionality, manufacturing costs, space, storage and assembly requirements. 
   U.S. Pat. No. 6,634,998 to Siaperas describes a portable exercise platform with a boxlike body, with a storage container with a hinged lid cover that flips up to convert into an inclined position. However, Siaperas does not teach for unit to convert with legs into a bench position high enough off the ground so user may assume many standard bench exercises. Siaperas uses clip rings to attach different multi lengths of resistance elements, but does not teach for permanently attached, self contained selectively adjustable resistive elements. With the Siapieras unit a user must stop exercising and get off the unit, taking time to unclip and manually change the resistance by adding or subtracting different resistance bands of different lengths or strengths to the clip. Thus, the Siaperas device is not practical to be easily used. 
   U.S. Pat. No. 6,558,301 to Jackson describes a platform with a transportable box like body containing a lid for storage, with hook type members to attach resistive elements. However, similar to Siaperas unit, the Jackson device does not describe converting the unit into a bench, and does not describe any types of permanently attached, self contained, selectively adjustable resistance elements. Similar to Siaperas, this device also requires the user to stop exercising and get off the unit, which takes time to unclip and manually change the resistance by adding or subtracting different resistance bands of different lengths or strengths to the clip. Thus, the Jackson unit is also not practical to be easily used. 
   U.S. Patent Application Publication 2006/0128540 to Engle describes a multi function exercise platform marketed worldwide under the name (MY GYM). Engle shows a portable exercise platform with fixed attached resistance tubes of several different diameters to allow for adjustment of strength, with permanently attached bands contained within the platform housing. 
   However this apparatus is deficient in several manners. Engle does not allow for converting the platform to a bench or a chair, which limits the exercises that are capable of being preformed from other upright positions. This devices does not allow for self contained storage for bar &amp; handle attachments. To change resistance in strength, the user also must stop the exercise, get off unit, open the attachment clips and add additional tubes of different diameters and strengths to the clip rings located on the outside of the body chamber. 
   Engle also does not allow for a selectable adjustment in length of the resistance tubes which is necessary for selectable range of resistance due to the height differences of the user and starting point required for some exercises, which restricts the exercises as well as the force needed to exert during the exercises. The resistance tubes permanently contained within the housing are not replaceable by the user once their lifespan has run out. Typical resistance tubes can have an average life span with normal use of about 1 year, due to conditions of being worn-out, overstressed, damaged, torn, dry, etc. Thus, once the lifespan of the tubes runs out, the Engle unit can become unsafe, useless and potentially dangerous to subsequent users. 
   Thus, the need exists for solutions to the above problems, deficiencies and shortcomings with the prior art. 
   SUMMARY OF THE INVENTION 
   A primary objective of the present invention is to provide a portable, convertible and multifunction exercise device, apparatus, system and method of use that combines the benefits of a stepper, bench, and resistance bands, into a multifunction gym, while overcoming the deficiencies and drawbacks of using each of these devices separately. 
   A secondary objective of the present invention is to provide a new and improved, uniquely engineered, versatile, low cost, portable, convertible and multifunction exercise device, apparatus, system and method of use that combines the benefits of a stepper, bench, resistance bands, into a multifunction gym. 
   A third objective of the present invention is to provide a portable, convertible and multifunction exercise device, apparatus, system and method of use, in a safe, sturdy, lightweight, portable, self contained unit capable of being used to perform a total body workout regime to encompass all muscle groups, arms, legs, shoulders, back, chest, hips, and abdominals. 
   A fourth objective of the present invention is to provide a portable, convertible and multifunction exercise device, apparatus, system and method of use for allowing a configurable, and transformable apparatus to convert from a step to a incline bench/chair which allows users to perform exercises in standing, sitting, kneeling, bending, squatting, or lying down, positions. 
   A fifth objective of the present invention is to provide a portable, convertible and multifunction exercise device, apparatus, system and method of use platform that can be used in conjunction with self contained resistance elements having selectable visibly marked variable increment levels of resistance. 
   A sixth objective of the present invention is to provide a portable, convertible and multifunction exercise device, apparatus, system and method of use that allows the user to selectively alter length of resistance elements, while in the operative position, without disembarking off the unit thus allowing the user rapid succession of exercise without any changeover of additional band lengths or strengths, thru a lockable plunger and reel system. 
   A seventh objective of the present invention is to provide a portable, convertible and multifunction exercise device, apparatus, system and method of use invention that has the versatility of multiple stations that can be used laterally or unilaterally, vertical or horizontal, dependent or codependent, and can be used by one or two persons at the same time, depending on the use of connective handles, bars, and attachments provided. 
   An eighth objective of the present invention is to provide a portable, convertible and multifunction exercise device, apparatus, system and method of use invention that can use accessory equipment such as but not limited to connective handles, bars, attachments, and the like, that can be conveniently stored within a storage compartment of unit itself. 
   A ninth objective of the present invention is to provide a portable, convertible and multifunction exercise device, apparatus, system and method of use invention that allows the user to replace resistance elements as required on an as needed basis, due to their limited lifespan. The lifespan of the resistance elements running out due to their being worn, torn, damaged, frazzled, frayed, dry, overstressed, or brittle, and the like. 
   A tenth objective of the present invention is to provide a portable, convertible and multifunction exercise device, apparatus, system and method of use invention that is collapsible for storage underneath a bed or closet or other convenient location. 
   An embodiment of the portable, convertible and multifunction exercise apparatus, can include a rectangular platform having a front end, a rear end, a left side and a right side, an elongated resistive band having a proximate end and an outer end, a length adjusting member for attaching the proximate end of the elongated resistive member to the rectangular platform, the length adjusting member for selectively controlling the length of at least one elongated resistive band. 
   The apparatus can have a pair of elongated resistive bands extending from one end or side of the platform. The apparatus can have a second pair of elongated resistive bands extending from an opposite end or opposite side of the platform. 
   The length adjusting member can be a rotatable wheel The length adjusting member can be a spring biased rotatable wheel which allows the proximate end of the elongated band to automatically be biased to roll up onto the wheel, so that pulling out the band pulls against a spring. 
   The apparatus can further include a pin or a spring loaded plunger for locking the wheel in a fixed position while the band has been pulled out to a desired and selected longitudinal length. 
   The wheel can also have a plurality of slots about a side wall of the wheel for allowing the pin or the protruding tip end of the plunger to be positioned therein locking the wheel in position. 
   The wheel can also have a keyhole slot having a large opening adjacent to a narrow opening, the large opening for allowing an enlarged portion on the proximate end of the band to be inserted and locked in place when being slid into the narrow opening, and the keyhole slot allowing for the band to be easily removed and replaced. 
   The apparatus can also have a central tubular member having a rotatable exterior surface portion, a left member having a left band attachment portion, the left member extending from a left end of the central tubular member, the left attachment portion being removable attachable to a left elongated resilient band that is also attached to a portion inside of the platform, a right member having a right band attachment portion, the right member extending from a right end of the central tubular member, the right attachment portion being removably attachable to a right elongated resilient band that is also attached to another portion inside of the platform, wherein the central tubular member being rotatable relative to the left member and the right member. 
   The apparatus can have an elongated member having extendable ends, wherein each of the extendable ends are connected to resistive bands that are connected to the platform. 
   The platform can also have at least one pair of foldable legs for converting the platform from a stepper to bench. 
   An interior storage compartment can be located on the platform for storing accessory items inside the platform. 
   The platform can also have a raisable lid which converts the platform to an inclined chair. 
   The platform can also have wheels for allowing the platform to be portable. 
   A method of using a portable, convertible and multifunction exercise apparatus for different exercises, can include the steps of providing a rectangular platform, providing an elongated resistive band with a proximate end, an outer end and a length therebetween, attaching the proximate end of the elongated resistive band to an inside portion of the platform, and selectively adjusting the length of the elongated resistive member for different exercises between a longer length having less resistance to a shorter length having more resistance. 
   The length adjusting can be accomplished by rolling and unrolling the proximate end of the band on a wheel, such as a spring biased wheel inside of the platform. The method can also include the step of locking the band at selected lengths while portions of the band are rolled about the wheel inside of the platform. 
   Further objects and advantages of this invention will be apparent from the following detailed description of the presently preferred embodiments which are illustrated schematically in the accompanying drawings. 


   
     BRIEF DESCRIPTION OF THE FIGURES 
       FIG. 1  is a top perspective view of the novel portable, convertible, multifunction exercise apparatus 
       FIG. 2  is a bottom perspective view of the apparatus of  FIG. 1 . 
       FIG. 3  is a top view of the apparatus of  FIG. 1 . 
       FIG. 4  is a front view of the apparatus of  FIG. 1 . 
       FIG. 5  is a bottom view of the apparatus of  FIG. 1 . 
       FIG. 6  is a left view of the apparatus of  FIG. 1 . 
       FIG. 7  is a right view of the apparatus of  FIG. 1 . 
       FIG. 8  is a top perspective view of the apparatus of  FIG. 1  with legs opened to a bench position. 
       FIG. 9  is a bottom perspective view of the apparatus of  FIG. 9  with legs open. 
       FIG. 10  is a top view of the apparatus of  FIG. 9  with legs open. 
       FIG. 11  is a front view of the apparatus of  FIG. 9  with legs open. 
       FIG. 12  is a bottom view of the apparatus of  FIG. 9  with legs open. 
       FIG. 13  is a left view of the apparatus of  FIG. 9  with legs open. 
       FIG. 14  is a right view of the apparatus of  FIG. 9  with legs open. 
       FIG. 15  is a top perspective view of the apparatus of  FIG. 1  storage lid open to transform the bench to an inclined chair position with an inclined backrest. 
       FIG. 16  is a side view of the apparatus of  FIG. 15  with lid open to an inclined position. 
       FIG. 17  is a cross-sectional view of the apparatus of  FIG. 15  along arrows  17 X in an up most inclined position. 
       FIG. 18  is another view of  FIG. 17  with backrest at an extended inclined position. 
       FIG. 19  is another view of  FIG. 17  with backrest support bar rotating to storage position. 
       FIG. 20  is another view of  FIG. 19  with backrest support bar in storage position. 
       FIG. 21  is another view of  FIG. 19  with lid in closed position on platform. 
       FIG. 22  is a top exploded view of the components of the apparatus of preceding figures. 
       FIG. 23  is a bottom exploded view of the apparatus components of  FIG. 22 . 
       FIG. 24  is a perspective view of the accessory bar assembly with extendable ends that can be used with the apparatus of the preceding figures. 
       FIG. 25  is an exploded view of bar assembly of  FIG. 24 . 
       FIG. 26  is a perspective view of the bar assembly of  FIG. 24  with attached grip handles. 
       FIG. 27  is an exploded view of the bar assembly detached from the grip handles. 
       FIG. 28  is a perspective view of the  FIG. 26  bar assembly with retracted handles. 
       FIG. 29  is a perspective view of the  FIG. 26  bar assembly with extended handles. 
       FIG. 30  is a top view of the bar assembly with handles of  FIG. 26 . 
       FIG. 31  is a front view of the bar assembly with handles of  FIG. 26 . 
       FIG. 32  is a top view of the bar assembly of  FIG. 26  without handles. 
       FIG. 33  is a front view of the bar assembly of  FIG. 26  without handles. 
       FIG. 34  is a perspective view of a handle used with the bar assembly of  FIGS. 24-33 . 
       FIG. 35  is a top view of the handle of  FIG. 35 . 
       FIG. 36  is a front view of the handle of  FIG. 35 . 
       FIG. 37  is a top view of apparatus of  FIGS. 1-23  with Backrest/Storage Lid removed to show storage of the handles, bars and leg straps 
       FIG. 38  is a front perspective view of the optional leg strap that can be used with the apparatus. 
       FIG. 39  is a side perspective view of the strap of  FIG. 38 . 
       FIG. 40  is a top view of the strap of  FIG. 38 . 
       FIG. 41  is a side view of the strap of  FIG. 38 . 
       FIG. 42  is a perspective view of the resistance band length being adjusted to the platform. 
       FIG. 43  is a perspective view of  FIG. 42  showing band markings on the resistance band. 
       FIG. 43A  is an enlarged portion of markings on the resistance band of  FIG. 43 . 
       FIG. 44  is another view of the platform of  FIG. 42  with a locked in length resistance band. 
       FIG. 45  is a partial inside view of the tension assembly with locked in length band. 
       FIG. 45A  is a top view of  FIG. 45  along arrow  45 Y with spring plunger locked in. 
       FIG. 46  is another view of  FIG. 45  with the plunger retracted to allow band lengthening. 
       FIG. 46A  is a top view of  FIG. 46  along arrow  46 Y of the spring plunger being pulled out. 
       FIG. 47  is another view of  FIG. 45  with the band locked into an extended length. 
       FIG. 48  is an enlarged perspective view of the tension assembly of  FIGS. 45-47  with spring cover removed. 
       FIG. 48A  is a partial side view of the tension assembly of  FIG. 48  along arrow  48 X. 
       FIG. 49  is an exploded view of the parts of the tension assembly of  FIG. 48 . 
       FIG. 50  is a perspective view of hub with resistance band to be installed. 
       FIG. 51  is another view of the hub of  FIG. 50  with an installed resistance band. 
       FIG. 52  is still another view of the hub of  FIGS. 50-51  with installed band. 
       FIG. 53  shows a user doing “Side Lateral Raises” using single grip handles standing on the apparatus platform. 
       FIG. 54  shows a user doing “Bicep Curls” using bar attachment standing on the apparatus platform. 
       FIG. 55  shows a user doing “Upright Rows” using bar attachment standing on top of the apparatus platform. 
       FIG. 56  shows a user doing “Squats” using bar extended standing on top of the apparatus platform. 
       FIG. 57  shows a user doing “Shoulder Raises” using bar extended standing on top of the apparatus platform. 
       FIG. 58  shows a user doing “Leg Extensions” using ankle attachments sitting on top of the apparatus in an inclined bench position. 
       FIG. 59  shows a user doing “Leg Curls” using ankle attachments laying face down on top of apparatus in bench position. 
       FIG. 60  shows a user doing a “Bench Press” using extended bar attachment sitting on the bench in an inclined position. 
       FIG. 61  shows a user doing “Tricep Extensions” using bar attachment sitting on the bench in an inclined position. 
       FIG. 62  shows a user doing “Abdominal Crunch” using both handle and ankle attachments laying face up on top of the unit in bench position. 
       FIG. 63  shows the hub assembly being assembled to the platform base. 
       FIG. 64  shows the spring plunger being attached to the hub assembly on the platform base. 
       FIG. 65  shows the hub axle fitting in the platform base side wall. 
       FIG. 66  shows the spring plunger being pulled out from the hub assembly. 
       FIG. 67  shows the resistance band being pulled out from the hub assembly of  FIG. 66 . 
       FIG. 68  shows the spring plunger locking the hub into position with the band pulled out. 
   


   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Before explaining the disclosed embodiments of the present invention in detail it is to be understood that the invention is not limited in its applications to the details of the particular arrangements shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation. 
   A listing of the components is described below.
       10 . Platform     20 . Bar Assembly     22 . left exposed outer end     23 . flat topped cylindrical opening     25 . inner tube     28 . right exposed outer end     29 . flat topped cylindrical opening     30 . Handle     32 . Hollow pipe end     33 . upper hole     38 . capped end     34 . gripping wrap tube     40 . Strap     44 . main horseshoe portion     45 . hook and loop outer surface     46 . one end  46       50 . Tension Hub Assembly     60 . Base     62 . left end wall     63 . rear end channel with inner ribs     64 . rear wall     65 . hole     66 . right end wall     67 . upper front end channel with inner ribs     68 . front end wall     70 . Backrest/Lid     72 . base of backrest/lid     73 . receiving groove     75 . hinge for backrest/lid     74  upper end/right end of backrest/lid     76 . nonmovable seat base     80 . Spring Plunger     82 . ball shaped handle     88 . protruding tip     90 . Stabilizer Beam     100 . Roller wheels     110 . Backrest Support Bar     112 . T-shaped bottom     118 . pivoting upper end     120 . Lifting Handle     130 . Dual Legs     132 ,  134  two vertical leg members     133 ,  135  L-shaped upper ends     136 . lower cross-member     137 ,  139  pivot points     140 . Resistance Bands     150 . Strength Marking     160 . Fastening Loop     170 . Hub Housing     180 . Axle     190 . Retention Ball     200 . Coil Spring     210 . Spring Cover     220 . Retention Slot     230 . Fastening Hook     236 . loop end     238 . Attachment belt     240 . Diameter adjusting strap (Velcro®)     245 . hook and loop surface     250 . Backrest Adjustment Slots     260 . Extendable Bar Ends/Adjustable Extension Bar     263 . length adjusting holes     266 . outer end     267 . depressible upwardly spring biased pin     270 . Extension Bar Latch Button     272 . Press portion with raised surface edging (overlies spring)     275 . pivoting portion     278 . latch portion with lower protruding pin     280 . Free Rotating Grip Tube     290 . Hub Lock Holes     300 . Resistance Band Egress Hole.     310 . Coil Spring retaining slot in Axle (# 180 )     320 . Coil Spring retaining tab on Hub (# 170 )     330 . Knuckle on Coil Spring for retention     340 . Tab on Coil Spring for retention     350 . Square Cutout in Base wall to retain Axle (# 180 ).     352 . base wall
 
Platform with Legs Retracted
   

     FIG. 1  is a top perspective view of the novel portable, convertible, multifunction exercise apparatus platform  10  with dual legs  130  in closed position for a floor engaging platform position.  FIG. 2  is a bottom perspective view of the apparatus  10  of  FIG. 1 .  FIG. 3  is a top view of the apparatus  10  of  FIG. 1 .  FIG. 4  is a front view of the apparatus  10  of  FIG. 1 .  FIG. 5  is a bottom view of the apparatus  10  of  FIG. 1 .  FIG. 6  is a left view of the apparatus  10  of  FIG. 1 .  FIG. 7  is a right view of the apparatus  10  of  FIG. 1 . 
   Referring to  FIGS. 1-7 , the apparatus  10  can initially have a platform floor engaging position. The platform  10  can have a generally rectangular shape having a base  60  with short left and right left and right end walls  62 ,  66  and longer front and rear walls  64 ,  68 , and a top surface having a nonmovable seat portion  76  and initially horizontal backrest  70 , both of which can have raised dimples so as to form a nonslip surface for the user. Alternatively, a recessed area on the upper surface of the platform can include a pad formed from but not limited to rubber, elastomers, foam, plastic, and the like. The platform  10  can be molded into a single structured element of plastic or other materials. 
   Extending out from two egress holes  300  in the left end wall  62  can be elastic bands (elongated resistive bands)  140  each have an outer end attached to either a fastening loop  160  or a fastening hook  230 . Likewise extending out from two egress holes  300  in the right end wall  66  can be additional elastic bands (elongated resistive bands)  140  each have an outer end attached to either a fastening loop  160  or a fastening hook  230 . The platform  10  can have a total of four elastic bands (elongated resistive bands) that can be length adjustable relative to the base  60 . More or less bands can be used as needed. For example, pairs of bands can be connected through different locations through other egress holes on sides as well as the ends of the platform  10 . 
   Each of the four elastic bands can be adjusted in length individually by spring plunger(s)  80  by rotatable tension hub assembly ( 50 ) and hub  170 , which will be described in greater detail in reference to  FIGS. 42-52 . 
   Two rollers (wheels)  100  can be rotatably attached beneath the left end wall  66  of the base  60  to allow the platform  10  to be portable and roll on floor/ground surfaces when the right end wall is raised and being dragged by lifting handle  120 . 
   Raised Bench Position 
     FIG. 8  is a top perspective view of the apparatus  10  of  FIG. 1  with dual legs  130  opened to a raised bench position.  FIG. 9  is a bottom perspective view of the apparatus  10  of  FIG. 9  with dual legs  130  open.  FIG. 10  is a top view of the apparatus  10  of  FIG. 9  with legs open.  FIG. 11  is a front view of the apparatus  10  of  FIG. 9  with legs  130  open.  FIG. 12  is a bottom view of the apparatus  10  of  FIG. 9  with legs  130  open.  FIG. 13  is a left view of the apparatus  10  of  FIG. 9  with legs  130  open.  FIG. 14  is a right view of the apparatus  10  of  FIG. 9  with legs open. 
   Referring to  FIGS. 1-14 ,  22 , and  23  each of the dual legs  130  has two vertical leg members  132 ,  134  with L-shaped upper ends  133 ,  135  that are pivotally attached by pivot points  137 ,  139  within stabilizer beams  90  underneath the base  60  of the apparatus  10 . The vertical leg members  132 ,  134  have a lower cross-member base  136  with lower protruding portions  138  which when the legs  130  are folded down raise the cross-member base  136  above the floor surface. As shown in  FIGS. 1-7 , the dual legs  130  can be initially folded toward one another and can be fully enclosed within base walls  62 ,  64 ,  66 ,  68 . In an open position (as shown in  FIGS. 8-14 ) the dual legs  130  bow outward to form a stable support to allow the apparatus to be used as a bench for the exercises to be described below. In the open position, the L-shaped upper ends  133 ,  135  can have flat upper surfaces which acts as a knuckle-stop to abut against inner roof surfaces of stabilizer bars  90 , providing a weight stabilized support for the platform  10 . 
   Inclined Chair Position 
     FIG. 15  is a top perspective view of the apparatus  10  of  FIG. 1  storage lid  70  open to transform the bench (of  FIGS. 8-14 ) to an inclined chair position with an inclined backrest  70 .  FIG. 16  is a side view of the apparatus  10  of  FIG. 15  with lid  70  open to an inclined position.  FIG. 17  is a cross-sectional view of the apparatus of  FIG. 16  with up most inclined position.  FIG. 18  is another view of  FIG. 17  with backrest  70  at an extended inclined position.  FIG. 19  is another view of  FIG. 17  with backrest support bar  110  rotating to storage position.  FIG. 20  is another view of  FIG. 19  with backrest support bar  110  in storage position.  FIG. 21  is another view of  FIG. 19  with lid  70  in closed position on platform  10 . 
   Referring to  FIGS. 15-21 , the backrest/lid  70  can rotate upward by hinge  75  relative to nonmovable seat base  76 , and held in place at a selected inclined angle by backrest support bar  110 . The upper end  118  of backrest support bar  110  can be pivotally attached to a midportion beneath the lid/backrest  70 . The bottom portion can have a T-shape  112  that allows the backrest support bar  110  to be positioned in individual pairs of the backrest adjustment slots  250  to adjust the angle of incline of the lid/backrest  70 . Moving the support bar  110  up against the lower surface face of the lid/backrest  70  into snappable U-shaped receiving groove  73 , allows the lid/backrest to be turned back into a bench configuration as shown in  FIG. 21 . 
     FIG. 22  is a top exploded view of the various components of the apparatus of the preceding figures.  FIG. 23  is a bottom exploded view of the various apparatus components of  FIG. 22 . Stabilizer beams  90  attach to base  60  by snapably fitting into parallel channels  63 ,  67 , each having inner rib tabs which allow for a tight fit. Channels  63 ,  67  are preferably molded into base  60  with the other components for the platform  10  being separately attachable to the base  60  as further described herein. Thus, all components other than the base  60  can be separately manufactured. 
   Bar Assembly 
     FIG. 24  is a perspective view of the accessory bar assembly  20  with extendable bar ends  260  that can be used with the apparatus  10  of the preceding figures.  FIG. 25  is an exploded view of bar assembly  20  with extendable bar ends  260  of  FIG. 24 .  FIG. 26  is a perspective view of the bar assembly  20  of  FIG. 24  with attached handles  30 .  FIG. 27  is an exploded view of the bar assembly  20  detached from the handles  30 .  FIG. 28  is a perspective view of the  FIG. 26  bar assembly  20  with retracted handles  30 .  FIG. 29  is a perspective view of the  FIG. 26  bar assembly with extended handles  30 .  FIG. 30  is a top view of the bar assembly with handles of  FIG. 26 .  FIG. 31  is a front view of the bar assembly  20  with handles  30  of  FIG. 26 .  FIG. 32  is a top view of the bar assembly  20  of  FIG. 26  without handles  30 .  FIG. 33  is a front view of the bar assembly  20  of  FIG. 26  without handles  30 .  FIG. 34  is a perspective view of a handle  30  used with the bar assembly  20  of  FIGS. 24-33 .  FIG. 35  is a top view of the handle  30  of  FIG. 35 .  FIG. 36  is a front view of the handle  30  of  FIG. 35 . 
   Referring to  FIGS. 24-35 , bar assembly  20  can include a grip tube  280  that freely rotates about a fixed inner tube  25 , so that a user can grip the grip tube  280  and lift and lower the bar assembly  20  while the inner tube  25  with exposed outer ends  22 ,  28  remains fixed. The inner tube  25  can have a left exposed outer end  22  with flat topped cylindrical opening  23  that allows a left flat topped extendable bar  260  to slide in and out therefrom. The inner tube  25  can also have a right exposed outer end  28  with flat topped cylindrical opening  29  that allows a right flat topped extendable bar  260  to slide in and out therefrom. A pair of pivotable spring biased bar latches  270  on the bar assembly  20  can each have a raised surface press-portion  272  that presses against a lower spring so that a latch portion  278  with lower protruding pin (not shown) can engage anyone of a row of increment adjustment holes  263  in the flat upper surface of extendable bar  26 . The bar latches  270  can allow for inner ends of each of the bars  260  to be retracted within side openings  23  and  29  of outer ends  22  and  28  of inner tube  25 . 
   Handles  30  with belt  238  attached fastening hooks  230  can have hollow pipe ends  32  with upper holes  33 . The hollow pipe ends  32  can slide about outer ends  266  of extendable bars  260  so as to allow for depressible spring loaded pins  267  on the bars  260  to pass into and lock with holes  33  so that handles  30  can be locked with bar assembly  20 . A gripping surface tube  34  can be wrapped about the pipe  32 , and the opposite end of the pipe  32  can have a cap  38 . 
   Storage Capability 
     FIG. 37  is a top view of apparatus of  FIGS. 1-23  with Backrest/Storage Lid  70  shown in the previous figures having been removed to show storage of the handles  30  and straps  40  and bar assembly  20 . 
   Referring to  FIGS. 1 ,  15 ,  22  and  37 , the raisable lid  70  can open up to three longitudinal compartments located about the parallel stabilizer beams  90  so as to be able to store separate components such as but not limited to the pair of handles  30 , pair of straps  40  and bar assembly  20  therein, when these components are not being used and/or when the apparatus  10  is being moved. 
   Leg Straps 
     FIG. 38  is a front perspective view of the optional leg strap  40  that can be used with the apparatus  10 .  FIG. 39  is a side perspective view of the strap  40  of  FIG. 38 .  FIG. 40  is a top view of the strap  40  of  FIG. 38 .  FIG. 41  is a side view of the strap  40  of  FIG. 38 . Referring to  FIGS. 38-41 , the straps  40  can have a main horseshoe portion  44  with one end  46  that is fixed to loop end  236  of the fastening hook  230 . The other end of the horseshoe portion  44  can have a fastening strap  240  such as a Velcro® strap with hook and loop surface portion  245  that can lock with hook and loop surface  45  on the outer perimeter of the horseshoe portion  44  of the strap  40 . Pulling the fastening strap  240  through the loop end  236  of the fastening hook  230  adjusts the diameter of the strap  40  to fit about different sized legs and/or ankles of the user. The straps  40  can be used with the leg exercises shown and described in relation to  FIGS. 58-59  which will be described later. 
   Wheel Hub Assembly Operation 
     FIG. 42  is a perspective view of the resistance band  140  length being adjusted to the platform  10 .  FIG. 43  is a perspective view of  FIG. 42  showing band markings  150  on the resistance band  140 .  FIG. 43A  is an enlarged portion of markings  150  on the resistance band of  FIG. 43 .  FIG. 44  is another view of the platform  10  of  FIG. 42  with a locked in length resistance band  140 .  FIG. 45  is a partial inside view of the tension assembly  50  with locked in length band  140 .  FIG. 45A  is a top view of  FIG. 45  along arrow  45 Y with spring plunger  80  locked in.  FIG. 46  is another view of  FIG. 45  with the plunger  80  retracted to allow band  140  to be lengthened.  FIG. 46A  is a top view of  FIG. 46  along arrow  46 Y of the handle  82  of the spring plunger  80  being pulled out.  FIG. 47  is another view of  FIG. 45  with the resistance band  140  locked into an extended length.  FIG. 48  is an enlarged perspective view of the tension assembly  50  of  FIGS. 45-47  with spring cover  210  removed.  FIG. 48A  is a partial side view of the tension assembly  50  of  FIG. 48  along arrow  48 X. Here, the hub  170  has the coil spring is about an axle  180  inside the hub  170 , and is held in place by a coil spring retaining slot  310  about a knuckle  330  on the coil spring  200 , and a coil spring tab  340  held in place by a coil spring retaining tab  320  on hub  170 .  FIG. 49  is an exploded view of the parts of the tension assembly  50  of  FIG. 48 . 
     FIG. 63  shows the hub assembly  170  being assembled to the platform base  60 .  FIG. 64  shows the spring plunger  80  being attached into a hole  65  the sidewall  64  on the platform base  60 .  FIG. 65  shows the square end of hub axle  180  fitting into a cut-out  350  in a base wall  352  inside of the platform base  60 . The square ends of hub axle  180  can be spring loaded so that the ends can be pushed inward against an inner spring (not shown) so that hub  170  is mounted in place, and the axle ends then can expand to snap into square cut-outs  350 . The snap in hub assembly  170  can be easily installed to the base  60  without extra tools or separate fasteners, such as screws, and the like, at any time during the manufacturing process of unit.  FIG. 66  shows the handle  82  of the spring plunger  80  being pulled out from the hub assembly  170 .  FIG. 67  shows the resistance band  140  being pulled out from the hub assembly  170  of  FIG. 66 .  FIG. 68  shows the spring plunger  180  locking the hub  170  into position with the band  140  having been pulled out. 
   Referring to  FIGS. 42-49 , and  63 - 68  each resistance band  140  can have markings  150  such as indicia being numbers, colors, etc. that allow the user to visually see selected incremental points on the length of each band  140  to determine desired resistance levels. The lengths of each of the resistance bands can be adjusted so that the longer the length of the resistance bands the less resistance (less force) the user gets during exercises. Likewise, the shorter the length of each of the resistance bands  140  the more resistance (more force) occurs during the exercises. The longer the band lengths the easier it is to stretch the bands  140  (less resistance). The shorter the band lengths the harder it is to stretch the bands  140  (more resistance). 
   Referring to  FIGS. 42-49 , and  63 - 68 , when the user wishes to change the length of the resistance bands  140  to accommodate for different exercises and/or levels of either negative or positive resistance, the user simply pulls out the ball handle  82  of the spring biased plunger  80  out of the locked position so that the protruding tip  88  disengages from the hub lock holes  290 . At the same time the user needs to be pulling out the fastening loop  160  located at ends of each resistance band  140 , out from the egress hole  300  until the selected level of resistance is reached by visual identification of the strength markings  150  imprinted on the resistance bands  140 . 
   As the user is pulling out the resistance bands  140  the coil spring  200  inside the hub  170  increases tension by winding up. When a selected level is achieved, the user simply releases ball handle  82  on the spring loaded plunger  80  which will then automatically lock the selected level by pushing tip end  88  into one of the hub lock holes  290 . Upon completion of an exercise, the user again simply pulls out the ball handle  82  of the spring loaded plunger  80  out of the locked position from one the holes of the hub lock holes  290  and the resistance band(s)  140  will automatically return to a starting wound up position, by the releasing of tension by unwinding of the coil spring  200  located within the hub housing  170  cap  210  which rotates about the axle  180 . 
   Changeable Resistance Bands 
     FIG. 50  is a perspective view of hub  170  with resistance band  140  to be installed.  FIG. 51  is another view of the hub  170  of  FIG. 50  with an installed resistance band  140 .  FIG. 52  is still another view of the hub  170  of  FIGS. 50-51  with installed band  140 . 
   Referring to  FIGS. 50-52 , the novel invention allows for removing resistance bands  140  so that different lengths of bands can be substituted, different types of bands, colors can be used, as well as replacing worn out bands and the like. The bands  140  can have an enlarged retension ball end  190  which allows the for band  140  to be easily attached to the hub  170  by passing the enlarged end  190  through the larger opening of a keyhole shaped slot  220  on the reel portion of the hub  170  and locking the band  140  to the hub  170  by sliding the enlarged end  190  behind the narrower opening of the keyhole slot  220 . Removing the band  140  when desired can be accomplished by reversing these steps. 
   Description of Exercises 
   The following descriptions below represent exercises from the main six muscle groups, ARMS, LEGS, BACK, SHOULDERS, CHEST, ABDOMINALS. Each muscle group has a subgroup in which multiple variations are possible in which the present invention also provides means to accomplish, this list is only an example of the many exercises possible with the present invention and is only meant to demonstrate the inventions versatility. The list of exercises is not intended to be an exhaustive list of the exercises capable of being performed; they are not necessarily in any order of any exercise regime and should not be construed as such. These are illustrative and not restrictive or limiting, and will be apparent to one who is practiced and skilled in the art. 
   Lateral Raises: 
     FIG. 53  shows a user doing “Side Lateral Raises” using single grip handles  30  standing on the apparatus platform  10 .  FIG. 53  is an illustration of the user standing in a vertical position atop the unit in folded down position grasping onto separate handles  230  connected by fastening hooks  230  to resistive elements  140 . The user then selects resistance level using the selectable plunger pin ( 80 - 88  previously shown), then raises arms from side simultaneously or one arm at a time to shoulder height, thus engaging the selected positive resistive force, then returning arms down with a negative resistance force. 
   Bicep Curls: 
     FIG. 54  shows a user doing “Bicep Curls” using bar attachment standing on the apparatus platform  10 .  FIG. 54  is an illustration of the user standing in a vertical position atop the unit in folded down position. With handles  30  attached and locked onto the extension bar  20 , the user then grasps the rotational padded portion of the bar with an underhand grip, with arms extended down from the sides, the user then curls the rotatable tube about bar  20  upwards and initiates the selected resistance force until arms are even with biceps, then returns bar to starting position. All during any exercise using the extension bar  20  the handles  30  remain in a fixed position due to the rotational padded portion of the bar  20 . This keeps the resistive elements  140  from being wound up. 
   Upright Rows: 
     FIG. 55  shows a user doing “Upright Rows” using bar attachment standing on top of the apparatus platform  10 .  FIG. 55  is an illustration of user standing in a vertical position atop the unit with the legs in a folded down position. With handles  30  attached and locked onto the extension bar  20 , the user then secures the bar  20  with an over handed grip, then raises bar  20  until it reaches under chin, then returns to starting position. 
   Squats: 
     FIG. 56  shows a user doing “Squats” using bar extended standing on top of the apparatus platform.  FIG. 56  is an illustration of the user positioned in a squatting position atop the unit with the legs in folded down position. With handles  30  attached onto the extension bar  20 , the bar  20  is extended to a selectable locked position on both sides to accommodate space to secure hands. The user then raises himself upwards to almost a vertical position with knees only slightly bent then returns to starting position. 
   Shoulder Raises: 
     FIG. 57  shows a user doing “Shoulder Raises” using bar extended standing on top of the apparatus platform  10 .  FIG. 57  is an illustration of the user standing vertical atop the unit with the legs in a folded down position. The handles  30  are attached and locked onto the extension bar  20 , and the bar  20  is extended out to a selectively locked position on both sides to accommodate space to secure hands. The user then raises the bar  20  from behind the neck upwards to a full overhead extension, then returns to the starting position. 
   Leg Extensions: 
     FIG. 58  shows a user doing “Leg Extensions” using ankle attachments  40  sitting on top of the apparatus in an inclined bench position.  FIG. 58  is an illustration of the user sitting in an inclined position atop the unit in the bench position. With the storage cover  110  opened and selectively adjusted and locked into the inclined position by bar  110 , the user then connects the ankle attachments  40  to the resistance elements  140  with fastening hooks  230 . After selecting the level of resistance, the user then extends legs out horizontally till they are level with the knees, and then returns to starting position. 
   Leg Curls: 
     FIG. 59  shows a user doing “Leg Curls” using ankle attachments  40  laying face down on top of apparatus  10  in a bench position with legs extending outward.  FIG. 59  is an illustration of the user laying face down horizontally on the unit in the bench position. After connecting the ankle attachments  40  to the resistive elements  140  by the fasteners  230 / 160 , the user then engages the resistance force by curling their feet and ankles toward the buttocks, and then returns to starting position. 
   Bench Press: 
     FIG. 60  shows a user doing a “Bench Press” using extended bar attachment  20  sitting on the bench  10  with expanded out legs in an inclined position.  FIG. 60  is an illustration of the user sitting in an inclined position atop the unit in the bench position. With the storage cover  70  opened and selectively adjusted and locked into the inclined position, the handles  30  are attached to the extension bar  20  in a locked position. The user then proceeds to push the bar  20  away from torso to fully extended arms, and then returns the bar  20  back in a controlled motion. 
   Tricep Extensions: 
     FIG. 61  shows a user doing “Tricep Extensions” using bar attachment  20  sitting on the bench  10  in an inclined position.  FIG. 61  is an illustration of the user sitting in an inclined position atop the unit in the bench position. With the storage cover  70  opened and selectively adjusted and locked into the inclined position, the handles  30  are attached to the extension bar  20  in a locked position. The user then proceeds to extend their arms up while keeping elbows in a fixed position, then returns to starting position. 
   Abdominal Crunch: 
     FIG. 62  shows a user doing “Abdominal Crunch” using both handle and ankle attachments  30 ,  40  laying face up on top of the unit  10  in a bench position.  FIG. 62  is an illustration of the user laying face up on unit  10  in the bench position. With the ankle attachments  40  secured and hands grasping handles  30 , the user assumes the crunch position trying to meet elbows to knees by pulling against the different pairs of resistive elements  140 . Afterward, the user returns in a controlled method to the starting position. 
   As previously described other types of exercises can be achieved with the novel invention. 
   While the invention has been described, disclosed, illustrated and shown in various terms of certain embodiments or modifications which it has presumed in practice, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended.
Portable, convertible and multifunction exercise apparatus, devices, systems and methods of using that allows individuals to accomplish their fitness, health conditioning, weight loss and rehabilitation goals with a single platform having selectively length adjustable resistance bands. Rotatable spring biased wheels can lock the bands to different lengths, where the longer the length the less resistance, and the shorter the length the more the resistance. The platform can transform from a stepper into a bench to an incline seat with foldable legs. Contained within the platform storage unit are several bars handles and leg attachments. An exercise bar having a rotatable midportion can have handle grip ends removably attachable to the bands and/or the bar so that a variety of additional exercises can be performed allowing the user to exercise all muscle groups for a total body workout.