a typical exercise apparatus of the present invention comprises a frame comprising a first a - shaped component comprising two first a - shaped component frame legs each having a distal end and a proximal end , wherein the first a - shaped component frame legs are hingedly attached at the distal ends thereby defining a first a - shaped component apex and a second a - shaped component comprising two first a - shaped component frame legs each having a distal end and a proximal end , wherein the second a - shaped component frame legs are hingedly attached at the distal ends thereby defining a second a - shaped component apex . such an apparatus also comprises a crossbar having a first crossbar end and a second crossbar end wherein the crossbar is disposed between the first a - shaped component and the second a - shaped component wherein the first crossbar end is slidably attached to a first a - shaped component frame leg and the second crossbar end is slidably attached to a second a - shaped component frame leg . such an apparatus also comprises one or more pulley systems attached to at least one a - shaped component frame leg , wherein the pulley system comprises one or more elongate elastic tension means having a proximal end removedly attachable to a frame leg and a distal end removedly attachable to the crossbar . further , such an apparatus comprises a seating means attached to the crossbar such that the weight of a user seated upon the seating means effects the depression of the crossbar thereby stretching and imparting tension to the elastic tension means attached to the crossbar . in certain embodiments of the apparatus the seating means is rotatably attached to the cross bar and is lockable . in certain embodiments of the apparatus the resistance imparted by the elastic tension means can be varied by engaging or disengaging individual elastic tension means or by lengthening or shortening individual elastic tension means . in certain other embodiments of the apparatus the proximal end of at least one of the two frame legs of each a - shaped component is attached to a base wherein the crossbar is configured to remain parallel to the plane of the base . in certain embodiments the apparatus further comprising elastic tension means handles removedly attachable to the one or more of the elastic tension means proximal ends . in certain embodiments the apparatus comprises a first l - shaped gripping means rotatably attached at the first a - shaped component apex and a second l - shaped gripping means rotatably attached at the second a - shaped component apex . in certain embodiments of the apparatus at least one of the first a - shaped component frame legs comprises a first telescoping tube and at least one of the second a - shaped component frame legs comprises a second telescoping tube . while in certain other embodiments the first l - shaped gripping means is attached to the distal end of the first telescoping tube and wherein the second l - shaped gripping means is attached to is attached to the distal end of the second telescoping tube and wherein at least one of the first telescoping tube and second telescoping tube comprises a locking means for setting the telescoping tube to any desired length . in certain embodiments of the apparatus the a l - shaped gripping means is attached to the distal end of a first telescoping tube and a second l - shaped gripping means is attached to the distal end of a second telescoping tube and wherein at least one of the first telescoping tube and second telescoping tube comprises a locking means for setting the telescoping tube to any desired length . in certain embodiments of the apparatus one or more of the pulley systems attached to one of the a - shaped component frame legs is at least partially disposed within that frame leg . a typical apparatus 10 of the present invention as illustrated in fig1 - 10 comprises a four - legged foldable a - frame 20 having a first frame leg 31 and second frame leg 32 , each having a distal end and a proximal end , are each configured to be parallel , and third frame leg 33 and fourth frame leg 34 , each having a distal end and a proximal end and configured to be parallel to one another . the distal ends of the first frame leg 31 and second frame leg 32 are hingedly attached to the distal ends of the third frame leg 33 and fourth frame leg 34 respectively by hinge assemblies 41 and 42 . in this embodiment the proximal ends of the first frame leg 31 and second frame leg 32 are fixedly attached to a first frame base 51 , while the proximal ends of the third frame leg 33 and fourth frame leg 34 are attached to a second frame base 52 ; and adjustable l - handgrips 53 and 54 are attached to the distal ends of the first frame leg 31 and second frame leg 32 to provide gripping means . in certain embodiments , such gripping means may be rotatably attached to the distal ends of the frame legs . in apparatus 10 the frame legs 31 , 32 , 33 and 34 are comprised of tubes having a multiplicity of perforations 55 extending completely through the walls of the tubes and configured along the longitudinal axes of the tubes . three first frame leg proximal end coaxial pulleys 61 are disposed and slidably attached at the proximal end of the first frame leg 31 and three second frame leg proximal end coaxial pulleys 62 are dispose and slidably attached at the proximal end of the second frame leg 32 . three third frame leg distal end coaxial pulleys 63 are disposed at the distal end of the third frame leg 33 and fourth third frame leg distal end coaxial pulleys 64 are disposed at the distal end of the fourth frame leg 34 . three elastic cords 71 , 72 , and 73 each having a distal end and a proximal end are disposed along the longitudinal axis of the first frame leg 31 and three elastic cords 74 , 75 and 76 each having a distal end and a proximal end are disposed along the longitudinal axis of the second frame leg 32 , wherein the proximal ends of the elastic cords 71 , 72 and 73 are removedly attached at a position along the longitudinal axis of the first frame leg 31 , such that the elastic cords 71 , 72 and 73 extend downward through first frame leg 31 coaxial pulleys 61 ; then upward along the longitudinal axis of the first frame leg 31 , through the third frame leg 33 distal coaxial pulleys 63 and then downward wherein the distal ends of elastic cords 71 , 72 and 73 are removedly attached to a crossbar 90 disposed between the third frame leg 33 and fourth frame leg 34 , wherein the ends of the crossbar 90 are slidably coupled to the third frame leg 33 and fourth frame leg 34 by means of crossbar coupling rollers 92 and 93 respectively such that the crossbar remains parallel to the plane of the base 52 and perpendicular to the third frame leg 33 and fourth frame leg 34 , while being slidably moveable along the longitudinal axes of the third frame leg 33 and fourth frame leg 34 . seating means in the form of two dual - component seats 91 are rotatably and adjustably attached to the crossbar 90 such that the weight of a user seated upon the dual - component seats 91 effects the depression of the crossbar 90 thereby stretching and imparting tension to the elastic cords attached to the crossbar 90 . additionally in the apparatus 10 of fig1 the of position proximal end coaxial pulleys 61 and 62 along the longitudinal axes of the frame legs 31 and 32 to which they are respectively attached can be varied . fig7 and 8 illustrates such positional variance . in fig7 crossbar 90 and the attached dual - component seats 91 are in a raised position , while in fig8 crossbar 90 and the attached dual - component seats 91 are in a lowered position . in certain embodiments the seating means is rotatably attached to the cross bar . in all of the various embodiments of the apparatus the elastic cords can be individually coupled to or detached from the frame such that the overall tension ( resistance ) of the apparatus can be easily varied to accommodate a variety of exercises and be customized according to the needs of the user . in embodiments such as apparatus 10 as is clearly depicted in fig1 , to the distal ends of elastic cords 71 , 72 , 73 , 74 , 75 and 76 comprise spherical elements 81 , 82 , 83 , 84 , 85 and 86 respectively , wherein each spherical elements has a diameter larger in than that of the chord to which it is attached . attached to the frame legs 31 and 32 are u - shaped elastic cords retaining elements 95 and 96 each comprising three u - shaped collars having diameters equal to or larger than the diameters of the elastic cords 71 , 72 , 73 , 74 , 75 and 76 inserted therein , but smaller than the diameters of the spherical elements 81 , 82 , 83 , 84 , 85 and 86 , such that the distal ends of elastic cords 71 , 72 , 73 , 74 , 75 and 76 are retained when inserted therein . additionally the attachment of the elastic cords retaining means 95 and 96 to the frame legs 31 and 32 is such that the positions of the retaining means 95 and 96 can be varied along the longitudinal axes of the frame legs 31 and 32 to which they are attached , such that the tension of the elastic cords 71 , 72 , 73 , 74 , 75 and 76 can be varied and adjusted . fig1 illustrates such positional variance of the elastic chord retaining element 91 along the longitudinal axis of frame leg 31 , wherein an upper position is depicted and a lower position is depicted in phantom by dashed lines and is denoted as ( 91 a ). fig1 also illustrates the apparatus 10 having handgrips 97 and 98 , which are removedly attached to the distal ends of elastics chords 71 and 74 respectively . additionally in the apparatus 10 of fig1 the of position proximal end coaxial pulleys 61 and 62 along the longitudinal axes of the frame legs 31 and 32 to which they are respectively attached can be varied . fig9 illustrates such positional variance of the elastic chord retaining coaxial pulleys 61 along the longitudinal axis of frame leg 31 , wherein coaxial pulleys 61 are in a lower position is depicted and wherein coaxial pulleys 61 in a raised position is depicted in phantom by dashed lines and denoted as ( 61 a ). since such an adjustment changes the effective the length , and therefore the tension , of the elastic cords 71 , 72 , 73 , 74 , 75 and 76 ; this adjustment provides yet another means for varying the resistance experienced by a user when performing various exercises . in certain preferred embodiments the foldable a - frame can be secured in either an open operational or folded storage position . fig1 - 5 depict the apparatus 10 in the open operational position , while fig6 depicts apparatus 10 in folded storage position . another embodiment of the present invention is the exercise apparatus 100 as illustrated in fig1 - 20 . the apparatus 100 comprises a four - legged foldable a - frame 110 having a first frame leg 115 and second frame leg 116 , each in the form of a rectangular tube having a frontal surface 121 , a rear surface 122 ( not visible in figs . ), and two side surfaces 123 , wherein each frame leg has a distal end and a proximal end ; and wherein first frame leg 115 and second frame leg 116 are configured to be parallel to one another . the a - frame 110 also comprises a third frame leg 131 and fourth frame leg 132 , each having a distal end and a proximal end ; and wherein first frame leg 131 and second frame leg 132 are configured to be parallel to one another . in apparatus 100 the frame legs 131 and 132 are comprised of circular tubes . the distal ends of the first frame leg 115 and second frame leg 116 are hingedly attached to the distal ends of the third frame leg 131 and fourth frame leg 132 respectively . the embodiment of the apparatus 100 further comprises two hinged cross - member assemblies 138 and 139 disposed between the proximal ends of first frame leg 115 and third frame leg 131 and the second frame leg 116 and fourth frame leg 132 respectively ; wherein the hinged cross - member assemblies each have two hingedly connected sections as clearly shown in fig1 , 13 , 15 , 16 , 17 and 18 . such hinged cross - members function to maintain the a - frame in an open position . additionally in the embodiment of the apparatus 100 the hinged cross - member assemblies 138 and 139 include locking components 138 a and 139 a respectively , wherein such a locking means functions to snap into a locking position wherein the two sections of each hinged cross member are disposed at a 180 ° angle such that the cross - member assemblies 138 and 139 are coplanar . additionally in the apparatus 100 the proximal ends of the first frame leg 115 and the second frame leg 116 are fixedly attached to a first frame base 135 disposed there between . adjustable l - handgrips 136 and 137 are rotatably disposed at the distal ends of the third frame leg 131 and fourth frame leg 132 respectively to provide gripping means . the rotating functionality of adjustable l - handgrips 136 and 137 is clearly illustrated in fig2 wherein forward positions of adjustable l - handgrips 136 and 137 are depicted and backward position adjustable l - handgrips 136 and 137 are depicted in phantom by dashed lines and are denoted as ( 136 a ) and ( 137 a ). as is illustrated in fig1 and 20 , in the apparatus 100 the adjustable l - handgrips 136 and 137 are attached to the ends of frame leg tubular members 133 and 134 respectively , which are telescopically couple to frame legs 131 and 132 respectively . by such an arrangement the positions of adjustable l - handgrips 136 and 137 can be slidably adjusted along the longitudinal axes of the frame leg tubular members 133 and 134 according to the needs of a user . fig1 depicts the adjustable l - handgrips 136 and 137 lengthened positions , while fig2 depicts the adjustable l - handgrips 136 and 137 in shortened positions . three proximal end coaxial pulleys 141 a are disposed at the proximal end of the first frame leg 115 and three proximal end coaxial pulleys 141 b are disposed at the proximal end of the second frame leg 116 and three distal end coaxial pulleys 142 a are disposed at each of the distal end of the first frame leg 115 and three distal end coaxial pulleys 142 b are disposed at each of the distal end of the second frame leg 116 . four elastic cords 151 a , 152 a , 153 a and 154 a each having a distal end and a proximal end are disposed along the longitudinal axis of the first frame leg 115 and three elastic cords 151 b , 152 b 153 b and 154 b each having a distal end and a proximal end are disposed along the longitudinal axis of the second frame leg 116 . the proximal ends of the elastic cords 151 a - 154 a and 151 b - 154 b each comprise a spherical element 155 having a diameter greater in than that of the chord to which it is attached . by means of the spherical elements 155 the elastic cords 151 a - 154 a and 151 b - 154 b are removedly attachable to a plurality of u - shaped collars 156 disposed at positions along the longitudinal axis of the frame legs 115 and 116 . by means of the spherical elements 155 and the u - shaped collars 156 the elastic cords 151 a - 154 a and 151 b - 154 b are attached to frame legs 115 and 116 , wherein the elastic cords 151 a - 154 a and 151 b - 154 b then extend downward through coaxial pulleys 141 a and coaxial pulleys 141 b respectively and then continue upward along the longitudinal axis of the frame legs 115 and 116 and through the coaxial pulleys 142 a and 142 b respectively . the distal ends of each of the elastic chords 151 a - 154 a and 151 b - 154 b comprise an attachment element in the form of a flange 166 configured to be removedly attachable to the crossbar 161 , wherein the flange functions as a hook . the crossbar 161 is disposed between the third frame leg 131 and fourth frame leg 132 , wherein the ends of the crossbar 161 are slidably coupled to the third frame leg 131 and fourth frame leg 132 respectively such that the crossbar 161 remains parallel to the plane of the base 135 and perpendicular to the third frame leg 131 and fourth frame leg 132 , while being slidably moveable along the longitudinal axes of the third frame leg 131 and fourth frame leg 132 . in fig1 the flanges 166 at the distal ends of elastic cords 153 a and 152 b are shown attached to crossbar 166 , while the flanges 166 at the distal ends of elastic cords 154 a and 151 b are depicted as unattached . additionally a lockable collar 168 is disposed about each of the frame legs 131 and 132 disposed beneath the crossbar 161 , wherein the lockable collars 168 functioning to limit the downward movement of the crossbar 161 . seating means in the form of a seat 165 is rotatably and adjustably attached to the crossbar 161 such that the weight of a user seated upon the seat 165 effects the depression of the crossbar 161 thereby stretching and imparting tension to any of the elastic cords attached to the crossbar 161 , wherein the depression of the crossbar 66 is limited by the position of the lockable collars 168 chosen by a user of the apparatus 100 . fig1 depicts the seat 165 and crossbar 161 of apparatus 100 in a raised position and fig1 depicts the seat 165 and crossbar 161 of apparatus 100 in a lowered position . fig1 also illustrates an embodiment of the apparatus 100 having two handgrips 158 , which are removedly attached to the distal ends of a one or more of the elastics chords 151 a , 152 a , 153 a , 154 a , 151 b , 152 b , 153 b and 154 b . the apparatus 100 can be retained an open position as illustrated in fig1 or a closed position as illustrated in fig1 . in apparatus 100 the proximal coaxial pulley systems 141 a and 141 b are disposed within the proximal ends of each of the first and second legs 155 and 116 respectively and each extends out partially through an opening in the frontal surfaces 121 of the proximal ends of the first and second legs as shown clearly in fig1 , 13 and 15 - 18 . the distal coaxial pulley systems are disposed within the distal ends of each of the first and second legs and extend out partially through an opening in the frontal surfaces 121 of the distal ends first and second legs as shown clearly in fig1 , 13 and 15 - 20 . in embodiments such as the embodiment of fig1 ( clearly depicted in fig1 and 14 ) a multitude of collar shaped elastic cord distal end retaining members are distributed at along the frontal surfaces of the distal ends first and second frame legs such that the distal ends of the elastic cord terminated with a ball retaining members can be secured in a variety of positions along the longitudinal axes of the first and second frame legs , thereby further providing a facile means of varying the resistance experienced by a user . a variety of exercises can be performed with apparatuses of the present invention . such exercises include , but are not limited to push - ups , pull - ups , lateral muscle pulls , squats , lunges , dips , hamstrings strengthening , bicep strengthening , and deltoid strengthening . fig2 illustrates a user in a traditional push - up position utilizing apparatus 10 to perform a push - up exercise , wherein the user &# 39 ; s frontal midsection is disposed upon the seats 91 attached to crossbar 90 , the users hands are disposed palms facing down in front of frame base 52 and the user &# 39 ; s feet are disposed behind frame base 51 and the one or more of the various elastic cords are disposed in selected positions to provide the user &# 39 ; s desired overall tension / resistance to the apparatus 10 . the user then performs the exercise by alternately raising and lowering the body in the manner of a traditional push - up exercise by the use of the arms while maintaining the body and legs in an extended straightened position . a method for performing a push - up exercise utilizing an apparatus of the present invention comprises the steps of : ( 1 ) disposing one or more of the elastic tension means in a selected position to provide a desired overall tension / resistance ; ( 2 ) disposing the frontal midsection of the body upon the seating means ; ( 3 ) disposing the hands with palms facing down in front of the frame while the feet are disposed behind frame and legs are straightened ; and ( 4 ) alternately raising and lowering the body by the use of the arms while maintaining the body and legs in an extended straightened position . fig2 is an illustration of a user utilizing exercise apparatus 10 to perform a lateral pull exercise , wherein the user &# 39 ; s right hand is gripping l - handgrip 53 , user &# 39 ; s right hand is gripping l - handgrip 54 , and user &# 39 ; s back rests upon the seats 91 attached to crossbar 90 . the heels of the user &# 39 ; s feet are disposed on the floor area behind frame base 51 and the various elastic cords are disposed in selected positions to provide the user &# 39 ; s desired overall tension / resistance to the apparatus 10 . a method for performing a lateral pull exercise utilizing an apparatus of the present invention comprises the steps of : ( 1 ) disposing one or more of the elastic tension means in a selected position to provide a desired overall tension / resistance ; ( 2 ) gripping the l - shaped handgrips with the right and left hand respectively ; ( 3 ) resting the lower back and / or buttocks upon the seating means with legs extended and feet disposed upon the surface outside of the frame ; and ( 4 ) alternately raising and lowering the body by the use of the arms while maintaining the body and legs in an extended straightened position . fig2 is an illustration of a user utilizing exercise apparatus 100 to perform a hamstring exercise , wherein the user &# 39 ; s right ankle is disposed in handgrip 158 , which is removedly attached to the distal end of a one of the elastics chord 151 b , 152 b , 153 b 154 b , wherein front of the user &# 39 ; s body faces the apparatus 100 while the user moves the fight leg back ( away from apparatus 100 ) while maintaining right leg in a straight position without bending the knee ; and wherein and the elastic cords selected from elastics chord 151 b , 152 b , 153 b 154 b is disposed in selected a position to provide the user &# 39 ; s desired overall tension / resistance to perform the exercise . fig2 is an illustration of a user utilizing exercise apparatus 100 to perform a hip abductor exercise , wherein the user &# 39 ; s right ankle is disposed in handgrip 158 , which is removedly attached to the distal end of the elastic chord 151 b , wherein left side of the user &# 39 ; s body faces the apparatus 100 while the user moves the right leg back ( away from apparatus 100 ) while maintaining the right leg in a straight position without bending the knee ; and wherein and the elastic cord elastics chord 151 b is disposed in selected position to provide the user &# 39 ; s desired overall tension / resistance to perform the exercise . fig2 is an illustration of a user utilizing exercise apparatus 10 to perform a squat exercise , wherein the user is seated on seats 91 , which are attached to crossbar 90 while the back if the user &# 39 ; s body is adjacent to the apparatus 10 such that the user is face away from the apparatus 10 ; and wherein the one or more of the various elastic cords are disposed in selected positions to provide the user &# 39 ; s desired overall tension / resistance to the apparatus 10 . the user performs the exercise by squatting and rising with arms extended to the front of the body . fig2 an illustration of a user utilizing an exercise apparatus 10 to perform a dip exercise , wherein user faces the apparatus 10 while user &# 39 ; s knees are resting upon seats 91 and user holds l - handgrips 53 and 54 and wherein one or more of the various elastic cords are disposed in selected positions to provide the user &# 39 ; s desired overall tension / resistance to the apparatus 10 . the user performs the exercise by alternatively pulling up and pushing down with arm muscles . fig2 an illustration of a user utilizing an exercise apparatus 100 to perform a biceps exercise , wherein the user stand upon frame base 135 facing away from the apparatus 100 and wherein the user &# 39 ; s hands with palms upturned hold the handgrips 158 , which are attached to elastic chords 151 a and 151 b respectively , and wherein the elastic cords 151 a and 151 b are disposed in selected positions to provide the user &# 39 ; s desired overall tension / resistance while performing the exercise . the user performs the exercise by pulling the hands towards the chest by bending arms at the elbow while maintaining the upper arms in contact with the upper torso . fig2 an illustration of a user utilizing an exercise apparatus 100 to perform a deltoid exercise , wherein the user stands erect upon frame base 135 while facing away from the apparatus 100 and wherein the user &# 39 ; s hands with palms downturned hold the two handgrips 158 , which are attached to elastic chords 151 a and 151 b respectively , and wherein the elastic cords 151 a and 151 b are disposed in selected positions to provide the user &# 39 ; s desired overall tension / resistance while performing the exercise . the exercise is performed by the user maintaining the arms in a straightened position in front of the body while alternately lifting and lowering the arms . since various embodiments of the apparatus can actually assist a user who cannot sufficiently perform exercises without assistance , it is especially adaptable and useful to individuals who may be handicapped or undergoing physical rehabilitation and the like . it is recognized that other modifications , methods , features , and advantages of the present invention will be or become apparent to one with skill in the art upon examination of the above drawings and description . it is intended that all such additional systems , methods , features , and advantages be included within this description , be within the scope of the present invention .
the present invention relates generally to exercise devices , and more specifically to exercise devices providing variable resistance when performing a wide variety of training movements . these exercise devices comprise a pulley system of elastic resistance bands or cords secured to a hinged a - shaped frame wherein the resistance imparted by the elastic bands or cords can be easily varied by engaging or disengaging individual resistance bands or lengthening or shortening individual bands .