an athletic training platform exercise device ( 10 ) is seen well in fig1 - 4 . the preferred embodiments of the device accomplish this by new and novel arrangements of elements and methods that are configured in unique and novel ways and which demonstrate previously unavailable but preferred and desirable capabilities . the detailed description set forth below in connection with the drawings is intended merely as a description of the presently preferred embodiments of the athletic training platform device ( 10 ), and is not intended to represent the only form in which the athletic training platform device ( 10 ) may be constructed or utilized . the description sets forth the designs , functions , means , and methods of utilizing the athletic training platform device ( 10 ) in connection with the illustrated embodiments . it is to be understood , however , that the same or equivalent functions and features may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the athletic training platform device ( 10 ). numerous alterations , modifications , and variations of the preferred embodiments disclosed herein will be apparent to those skilled in the art and they are all anticipated and contemplated to be within the spirit and scope of the belt - squat exercise device ( 10 ). for example , although specific embodiments have been described in detail , those with skill in the art will understand that the preceding embodiments and variations can be modified to incorporate various types of substitute and or additional or alternative materials , relative arrangement of elements , and dimensional configurations . accordingly , even though only few variations of the athletic training platform device ( 10 ) are described herein , it is to be understood that the practice of such additional modifications and variations and the equivalents thereof , are within the spirit and scope of the invention . what is claimed then , as seen well in fig1 - 4 , includes an athletic training platform exercise device ( 10 ) having a user enclosure ( 100 ) with a platform ( 130 ), wherein the platform ( 130 ) has a platform opening ( 160 ) allowing passage of a connecting means ( 230 ) connected to a resistance unit ( 200 ). the resistance unit ( 200 ) may provide variable resistance to the connecting means ( 230 ). one skilled in the art will realize that such a construction is ideally suited to “ squat ” type exercise , however , the teaching is specifically meant to reach beyond that to all forms of exercise where this type of resistance may be useful . the platform ( 130 ) may be supported by standards ( 140 ) supporting at least two side rails ( 110 ), or in some embodiments , three side rails ( 110 ), allowing for one side to remain open to access the platform ( 130 ) more easily . equally well , a fourth side rail ( 110 ) could be provided . in one series of embodiments , as seen well in fig1 - 2 , the resistance unit ( 200 ) may include at least one weight holder ( 220 ) movably positioned on a weight tower ( 210 ) allowing vertical motion of the weight holder ( 220 ). in yet another series of embodiments , not pictured , the resistance unit ( 200 ) may further include a resistance unit ( 200 ) producing a resistance selected from the types of resistance consisting of electrical , hydraulic and elastic resistance . in a further series of embodiments , the resistance unit ( 200 ) may further include a resistance unit ( 200 ) producing a variable resistance during a displacement of the connecting means ( 230 ). for such a series , the disclosures of u . s . patent application ser . no . 14 / 253 , 159 ; u . s . pat . publ . 20150290489 is explicitly disclosed as though fully rewritten herein . by way of example and not limitation , such a series of embodiments might be denominated a static - dynamic device , suitable for a quick - release method of training . in certain embodiments of a static dynamic exercise device , although one skilled in the art would recognize many other embodiments based on the principles taught herein , the device might include four basic components . the first is at least one spatially displaceable object having a predetermined mass , or in other embodiments , any source of resistance to movement . in several common embodiments , the spatially displaceable object will be one or more weights . there is no particular design for a weight to be configured , other than it having a predetermined mass or resistance ; shape or materials are inconsequential , although in common embodiments , steel weightlifting plates may be utilized . however , it is not necessary for the spatially displaceable object to be a weight , and it could also be a pressure piston , actuated within a pressure cylinder , a means of elastic resistance such as a spring or elastic band , or any other object that is capable of generating a static resistance when there is no movement , and with movement , is capable of creating a dynamic resistance . such a static - dynamic exercise device may include a resistance unit ( 200 ) coupled to the spatially displaceable object that is capable of producing a variable resistance to movement of the spatially displaceable object . the resistance unit may be capable of generating at least a resistance to movement equal to or greater than the user - applied force and the resistance unit ( 200 ) may be reversibly alternated between at least two predetermined levels of resistance . again , no particular construction is necessary for the resistance system , other than the requirement that it be capable of a first resistance preventing the user - applied force from displacing the spatially displaceable object , and that this resistance may be released such that the resistance system generates a second resistance less than the user - applied force , thereby allowing the user to spatially displace the spatially displaceable object . the second resistance may be , but is not necessarily , optimally as low as can be practically achieved , given the necessary constraints of friction within the mechanism . as detailed above , the term “ displace ” includes any form of variable resistance , particularly including that which may be provided by pneumatic or hydraulic pressure pistons , or by any form of providing elastic resistance . in one series of embodiments , the resistance unit ( 200 ) includes a pressure generator capable of creating a pressure in fluid communication with a resistance interlock . pressure produced by the pressure generator may be transmissible to the resistance interlock , thereby creating the variable resistance to movement of the spatially displaceable object . in a common series of embodiments , the pressure interlock creates the variable resistance to movement of the spatially displaceable object by means of a plunger or piston exerting a force against the connecting means ( 230 ). the resistance unit ( 200 ) may have a controller capable of regulating the pressure transmissible to the resistance interlock . in a typical embodiment , the resistance interlock may include a pneumatic , hydraulic , or electrically powered piston , such that the resistance interlock has a first position in which little or no force is applied by the resistance unit ( 200 ) and at least a second position wherein a force equal to that necessary to prevent movement of the connecting means ( 230 ) by application of a user - applied force is applied by the resistance unit ( 200 ). any controller may be capable of rapid alternation between the first and second positions . the resistance interlock may be reversibly capable of producing a variable resistance to movement of the connecting means ( 230 ), including at least a resistance in excess of the user - applied force and wherein the resistance unit ( 200 ) may be reversibly alternated between at least two predetermined levels of resistance . the at least two predetermined levels of resistance may include a level of no resistance to movement , other than the necessary constraints of friction within the mechanism , and a level of resistance capable of preventing movement of the connecting means ( 230 ) by the application of a user - applied force . thus , what is claimed includes an embodiment where the resistance unit ( 200 ) has a first position in which no resistance is applied by the resistance unit ( 200 ) and at least a second position wherein a resistance equal to that necessary to prevent movement of the connecting means ( 230 ) is applied by the resistance unit ( 200 ). the resistance unit ( 200 ) may be alternatable between the first position and the second position in a time interval of one second or less , while in another embodiment , the resistance unit ( 200 ) may be alternatable between the first position and the second position in a time interval of three seconds or less . generally , the shortest possible times between alternations of positions may be desirable , including times as low as one - tenth of a second . as described , in some embodiments , the claimed device ( 10 ), as seen well in fig1 - 3 , may have a weight tower ( 210 ) that includes a height adjustment ( 250 ) that establishes a limit on the vertical motion of the weight holder ( 220 ). this would , among other advantages , would allow an intermediate starting point for lifting a weight stack as well as to tend to prevent an “ overshoot ” if the weight is raised with unexpected force . in many embodiments , and as seen in fig1 - 4 , but not necessarily all , the connecting means ( 230 ) may be a cable ( 230 ) carried on at least one pulley ( 240 ). in certain embodiments , the connecting means ( 230 ) or cable ( 230 ) may be connected to a user interface ( 260 ), and this connection may be effected by means of a multi - axial connector allowing motion between the connecting means ( 230 ) and the user interface ( 260 ) in multiple axes . while other solutions would be known by one skilled in the art , such a multi - axial connector could be as simple as a swiveling shackle . the user interface ( 260 ) may be a harness ( 260 ) capable of at least partially surrounding a body of a user , while in other embodiments , the user interface ( 260 ) may be a hand - held user interface ( 260 ). in sum , any means of allowing the user to be coupled to the device ( 10 ) may be sufficient . as seen well in fig1 , the enclosure ( 100 ) may further include at least one back rail ( 150 ) connecting at least two standards ( 140 ). such rails ( 150 ) may help a user stayed centered on the platform ( 130 ) and in other embodiments , also seen well in fig1 , there may be at least one enclosure attachment ( 120 ) below a vertical level of the side rails ( 110 ) which may anchor resistance devices . such a resistance device or devices my produce a resistance selected from the types of resistance consisting of electrical , hydraulic and elastic resistance . all that is required of a resistance device ( 110 ) is that it increases a user effort necessary to displace the connecting means ( 230 ) and / or the user interface ( 260 ), or in some way changes the dynamics of the user effort . as discussed , such a change in dynamics could involve the user exerting force against an unyielding resistance , only to have that resistance modified at some point during the effort . in some embodiments , and especially in some devices as may be appreciated from u . s . pat . publication 20150290489 , the resistance device ( 120 ) may include a resistance device ( 120 ) producing a variable resistance during a displacement of the connecting means ( 230 ). such a variable resistance during the displacement of the connecting means ( 230 ) could include various patterns of resistance , e . g ., resistance increasing , decreasing or otherwise cycling between increasing and decreasing , during the displacement . in some embodiments , the device ( 10 ) is ideally suited to a quick - release method of training , where a connecting means may be locked against movement , and then suddenly released for maximal user effort . in another embodiments , an athletic training platform exercise device ( 10 ) can include a user enclosure ( 100 ) having a platform ( 130 ) supported by standards ( 140 ) supporting at least two side rails ( 110 ), as seen well in fig1 - 4 . the platform ( 130 ) may have a platform opening ( 160 ) allowing passage of a cable ( 230 ) carried on at least one pulley ( 240 ), which is in turn connected to a resistance unit ( 200 ) further comprising at least one weight holder ( 220 ) movably positioned on a weight tower ( 210 ) allowing vertical motion of the weight holder ( 220 ). with further reference to fig1 - 4 , the cable ( 230 ) may be further connected to a user interface ( 260 ) by means of a multi - axial connector allowing motion between the cable ( 230 ) and the user interface ( 260 ) in multiple axes . in such embodiments , the resistance unit ( 200 ) may provide variable resistance to the cable ( 230 ). in yet another embodiment , and again as seen in fig1 - 4 , an athletic training platform exercise device ( 10 ), may include a user enclosure ( 100 ) having a platform ( 130 ), wherein the platform ( 130 ) has a platform opening ( 160 ) allowing passage of a cable ( 230 ) connected to a resistance unit ( 200 ) capable of producing a variable resistance during a displacement of the connecting means . such resistance may be selected from the types of resistance consisting of electrical , hydraulic and elastic resistance including a variable resistance during a displacement of the connecting means ( 230 ). the cable ( 230 ) may be further connected to the user interface ( 260 ) by means of a multi - axial connector allowing motion between the connecting means ( 230 ) and the user interface ( 260 ) in multiple axes . and , as further described above , the device ( 10 ) may be constructed such the resistance unit ( 200 ) has a first position in which no resistance is applied by the resistance unit ( 200 ) to the cable ( 230 ) and at least a second position wherein a resistance equal to that necessary to prevent movement of the cable ( 230 ) may be applied by the resistance unit ( 200 ). numerous alterations , modifications , and variations of the preferred embodiments disclosed herein will be apparent to those skilled in the art and they are all anticipated and contemplated to be within the spirit and scope of the disclosed specification . for example , although specific embodiments have been described in detail , those with skill in the art will understand that the preceding embodiments and variations can be modified to incorporate various types of substitute and or additional or alternative materials , relative arrangement of elements , order of steps and additional steps , and dimensional configurations . accordingly , even though only few variations of the method and products are described herein , it is to be understood that the practice of such additional modifications and variations and the equivalents thereof , are within the spirit and scope of the method and products as defined in the following claims . the corresponding structures , materials , acts , and equivalents of all means or step plus function elements in the claims below are intended to include any structure , material , or acts for performing the functions in combination with other claimed elements as specifically claimed .