Patent Publication Number: US-8109863-B2

Title: Resistance exercise trainer and related speed training process

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a resistant exercise trainer and related speed training process. More particularly, the present invention relates to a resistance exercise trainer kit having a durable bag capable of retaining multiple safe weights for use in a related speed training process that enhances athletic endurance, speed and strength. 
     The popularity of training devices designed to improve athletic performance such as strength, speed and endurance have increased in popularity in recent years for both professional and amateur athletes. Accordingly, a wide variety of equipment and training regimens have been devised for athletes having a variety of skill levels. Training equipment has been designed for athletes involved in a variety of sports that include soccer, football, hockey, track and field, basketball, baseball, swimming, etc. The training devices are devised to improve physical performance by applying a drag force, weight or other impedance to the athlete during an exercise or training regimen. The restraints are specifically designed to resist athletic movement. Thus, the athlete must exert a greater than normal muscular effort to perform the exercise or training regimen. Restraints of this kind are particularly popular for improving athletic strength, speed and endurance. 
     One example of such a training device includes strapping weights to an athlete prior to running. During training, the athlete must overcome increased forces from the weights to reach normal running speed. The athlete also experiences a greater physical load over the duration of the entire training session. Once removed, the athlete may achieve higher speeds and longer distances since the body experiences less resistance and less work load due to the absence of the weights. Other athletes may use weighted sleds or skids that must be pushed or pulled in order to obtain additional resistance. For example, a cord extending from a sled connects to a belt strapped to an athlete. The athlete pulls the sled while running across an artificial turf or natural field. The athlete must exert a greater than normal muscular effort to drag the additional weight across the field. Alternatively, athletes may push weighted skids. These are particularly popular in football where offensive or defensive linemen push tackling dummies attached to a weighted skid to improve blocking or tackling skills in addition to building strength, speed and endurance. But, appropriate weight selection, attachment, distribution of weight to the body, and formulation of training regimens with respect to the above-identified devices are difficult. Moreover, weights and large, heavy sleds or skids are relatively expensive, difficult to adjust, certainly uncomfortable to wear and are inconvenient to store and transport due to the requisite quantity, weight and size. 
     More recently developed techniques use wind or water resistance through the use of a strap-on chute that increases resistance by collecting air or water during running or swimming. More specifically, U.S. Pat. No. 5,217,186 to Stewart et al. discloses a parachute designed to resist forward motion. The parachute is square shaped and has a number of attached parachute cords drawn through a spacing disk that prevents the cords from tangling. The parachute attaches to the athlete by a strap extending from the cords. The parachute opens in the wind during running and exerts a drag force on the athlete. In general, resistance exerted on the athlete is a function of the size and shape of the inflated parachute. Athletes may also experience larger drag forces at higher speeds. But, the Stewart parachute suffers from an inability to predictably change the resistance of the parachute. Changing resistance is important especially since athletes vary in weight, height, and most importantly, strength. Individual athletes may also require different resistances during different portions of a training regimen. Hence, an athlete must acquire multiple parachutes, each varying in size and possibly shape, to accommodate the need for multiple resistances. Another drawback of the Stewart parachute design is that an athlete will experience larger resistances and higher drag on windy days. Additionally, depending upon the direction of the wind, it may be difficult for the athlete to even inflate the parachute to obtain any resistance. The square parachute design in Stewart also does not always adequately catch wind and stay inflated, particularly during turns. Other similar prior art parachute devices tangle easily and may be unstable in both straight movement and upon turning. 
     Another parachute design is disclosed in U.S. Pat. No. 5,472,394 to Michaelson, which endeavors to solve the problems associated with Stewart. Michaelson discloses a parachute for use in speed and endurance training for amateur or professional athletes. The parachute is usable during running, biking, skating, etc. The parachute includes a set of cords that attach to an edge of the parachute at one end and commonly attach together to a strap, e.g. a belt worn by the athlete, at the other end. A regulator alters the free length of the cords and the corresponding shape of the inflated parachute. In turn, the athlete may adjust the resistance of the parachute by adjusting the length of the cords. The parachute sheet itself is formed with air pockets extending radially out from near the center of the sheet and terminating at the cord attachment points. The drag afforded by the parachute is adjusted by the degree of the opening of the pockets and the size of the inflated parachute. Shortening the length of the cords decreases the size of the inflated parachute and decreases the maximum drag. Increasing the length of the cords correspondingly increases the size of the inflated parachute thereby increasing the maximum drag. While the Michaelson design improves on adjustability in view of Stewart, it still fails to take into account predictable and reliable resistance. Like Stewart, Michaelson cannot control environmental factors such as wind, which ultimately affects the resistance exerted on the athlete. 
     Alternative resistance-based athletic training devices used to improve athletic performance include the aforementioned sleds or skids. Football players in particular use blocking sleds to improve endurance, speed and skills such as blocking or tackling techniques. Blocking sleds typically have a large, broad base and include a dummy positioned at one end thereof. The player contacts the dummy and drives the sled backwards. The player must exert significant energy to move the heavy and cumbersome sled backwards. A person may stand on the rear platform to add additional resistance and weight to the sled. 
     In another example, U.S. Pat. No. 6,942,585 to Krause discloses a moveable football training sled having a blocking dummy mounted to a front portion of an elongated frame. The front portion is generally flat and angled relative to a tipped rear portion. A wheel is mounted rearwardly of the front portion and midway between laterally opposite sides of the frame. A player strikes the blocking dummy, tilts the front portion back about the wheel and drives the sled backwards. The size and weight of the frame and tackling dummy provide weighted resistance to the athlete moving the frame. 
     Moreover, U.S. Pat. No. 6,261,194 to Hadar et al. discloses a one man football blocking sled capable of being interconnected to form a multiple-man tackling sled. The one-man tackling sleds are connected together by a bar that extends through and locks into a channel rigidly attached to each sled. Of course, increasing the number of connected sleds increases the weight of resistance of the training device. But, the multiple-man sled is designed to be used with multiple athletes. Accordingly, each athlete is assigned to “tackle” the corresponding dummy attached to each individual blocking sled. Thus, individual athletes will not experience an increase or decrease in resistance as other players using the tacking sled make up the difference in load. 
     Lastly, U.S. Pat. No. 2,237,600 to Gilman discloses a blocking sled having a set of runners secured to an upright arcuate member at one end. A spring secured above the lower portion of the arcuate member increases the resistance of the arcuate member in response to contact by the athlete. In this regard, the athlete drives into the arcuate member and forces the blocking sled rearwardly. Friction between the runners and the ground, and forces in the spring, provide the necessary resistance to work the athlete. Of course, the blocking sled includes padding on the free ends of the arcuate member driven by the athlete. This prevents physical contact of the athlete with the metallic arcuate member. 
     Unfortunately, the blocking or tackling sleds described above have several general drawbacks. For instance, the sleds are often expensive, difficult to move and require significant storage space relative to other training devices. While professional sports teams can typically easily afford such a training device, smaller football programs, such as a high school football program, may have difficulty raising the funds or finding the requisite storage space to house the training equipment. But, these training devices do reduce player-to-player contact and are particularly desirable because they reduce the number of injuries associated with contact between two players. Thus, athletes are able to train harder and longer without substantially increasing the risk of injury due to constant contact with other teammates. 
     There exists, therefore, a significant need for a versatile, safe and inexpensive resistance exercise trainer and related speed training process. Such a resistance exercise trainer should include a durable bag capable of storing one or more safe weights, should be attachable to a person, should provide relatively predictable resistance based on the quantity of safe weights in the bag and the surface along which the bag is dragged upon and should be easy to manufacture, inexpensive and compact. The present invention fulfills these needs and provides further related advantages. 
     SUMMARY OF THE INVENTION 
     The resistance exercise trainer generally includes an adjustable strap wearable by a user, a leash selectively attachable to the strap at a first end and a bag selectively attachable to a second end of the leash and configured for removable reception of at least one weight. The resistance exercise trainer provides resistance exercise training when a user wears the strap and pulls the bag and the weight with the leash such that the weighted bag impedes user movement. Impeding user movement in this regard is particularly useful for enhancing speed, strength and endurance. 
     More specifically, the strap may include a flexible belt, a harness or a vest designed to be selectively worn by the user. The strap may also include a selectively adjustable clip, hook and loop, buckle, tri-clip or a tri-glide that enables the resistance exercise trainer to selectively fit users that vary in size. The weight pulled by the strap and the leash preferably includes a low-impact filling designed to prevent injury upon impact. For example, the low-impact filling may include granules, pellets or low-density beads. In one embodiment, the low-impact filling is permanently heat sealed within the interior of the weight. In an alternative embodiment, the weight includes a sealable compartment for selectively filling or emptying the low-impact filling. In this embodiment, the compartment may include a sleeve that has a double reinforced zipper for forming an air and water tight seal. The leash itself may be configured for individual use as jump rope, while the weight may also be configured for individual use in weight lifting exercise. In this regard, the weight may further include a hand grip to increase the versatility of using the weight in associated strength training exercises. 
     The bag itself is preferably manufactured from a stretchable material capable of accommodating multiple weights therein. In a particularly preferred embodiment, the bag is configured to retain the leash and the strap in addition to multiple weights. The bag may further include an internal handle for transporting the multiple weights, the leash and the strap all within the bag. The bag also includes an aerodynamic tear-drop shape that conceals the internal handle and a coupler that engages the leash to the bag during resistance exercise training. An internal adjustable retainer may also be used to secure one or more of the weights inside of the bag to prevent shifting while performing resistance exercise training. The user may further activate a quick-release mechanism coupled to the strap for selectively detaching the leash from the strap on-the-fly, thereby leaving behind the leash, the bag and the one or more weights secured therein. This quick-release mechanism may be particularly preferred during speed burst exercises wherein the user experiences a sudden release of resistance once the bag is detached from the strap. 
     Furthermore, a resistance exercise training process is used in association with the resistance exercise trainer. Such a process includes the steps of connecting a strap to a first end of the leash, attaching a bag to the second end of the leash, inserting a weight into the bag and then affixing the strap to a user. Then, the user pulls the bag and the weight with the strap through connection with the leash, wherein the weighted bag impedes user movement thereby accomplishing resistance exercise training. As part of the inserting step, a user may secure one or more of the weights inside the bag to prevent shifting during use. In a particularly preferred embodiment, the inserting step includes the step of adding multiple weights to the bag thereby increasing the resistance experienced during the resistance exercise training. The resistance exercise training process may further include the step of releasing the leash from the strap while pulling the weighted bag on-the-fly so the user can work on speed burst training. 
     The resistance exercise training process further includes the steps of filling or emptying the weight with low-impact material. For example, after filling the weight, the user seals the low-impact material inside of the weight with a water or air tight seal. This ensures that none of the low-impact material escapes the weight during any of the resistance exercise training regimens disclosed herein. Furthermore, such a resistance exercise training process may include the steps of disconnecting the leash from the strap, detaching the leash from the bag and exercising with the leash and the weight individually. In this embodiment, the leash is used for jumping rope and the weight is used for lifting during strength training exercises. In a particularly preferred embodiment, the user may resize the leash for easily jumping rope. Once the user is done using the resistance exercise trainer, the weights, the leash and the strap may be stored inside the bag. A handle inside of the bag may be used to carry the weight, the leash and the strap to a storage location. 
     Other features and advantages of the present invention will become apparent from the following more detailed description, when taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings illustrate the invention. In such drawings: 
         FIG. 1  is a perspective view illustrating a resistance exercise trainer, including a bag, a set of safe weights, a belt and a leash; 
         FIG. 2  is a perspective view of the resistance exercise trainer bag; 
         FIG. 3  is a perspective view of the bag including a reinforcement patch; 
         FIG. 4  is an enlarged view taken about the circle  4  in  FIG. 3 , illustrating the contour of the outer surface of the bag; 
         FIG. 5  is a perspective view of the bag and several internal components; 
         FIG. 6  is a side view of the bag, illustrating the bag in an open position; 
         FIG. 7  is a perspective view illustrating grasping the bag by a pair of internal handles; 
         FIG. 8  is a partially cut-away perspective view of the bag illustrating a pair of internal straps for securing the safe weights; 
         FIG. 9  is a cross-sectional view of the bag taken about the line  9 - 9  in  FIG. 6 , further illustrating the internal components of the bag; 
         FIG. 10  is a schematic view illustrating insertion of a plurality of safe weights into the bag; 
         FIG. 11  is another schematic view illustrating picking up a plurality of the safe weights in the bag with the handles; 
         FIG. 12  is a perspective view of the safe weight; 
         FIG. 13  is a cross-sectional view of the safe weight taken about the line  13 - 13  in  FIG. 12 , illustrating a plurality of granules within the safe weight; 
         FIG. 14  is a perspective view of a refillable safe weight; 
         FIG. 15  is a cross-sectional view taken about the line  15 - 15  in  FIG. 14 , illustrating filling the safe weight through a sleeve; 
         FIG. 16  is an alternative cross-sectional view of  FIG. 15 , illustrating attachment of a pair of internal zippers; 
         FIG. 17  is another cross-sectional view of the safe weight of  FIG. 15 , illustrating the sleeve triple sealed to the encasement of the safe weight; 
         FIG. 18  is an enlarged view taken about the circle  18  in  FIG. 17 , illustrating the sleeve triple sealed to the encasement of the safe weight; 
         FIG. 19  illustrates an environmental view of the resistance exercise trainer in use; 
         FIG. 20  is an environmental view illustrating disconnection of the leash from the belt on-the-fly via a quick release mechanism; 
         FIG. 21  is an environmental view illustrating an exercise using the safe weight; 
         FIG. 22  is an environmental view illustrating use of the leash as a jump rope; and 
         FIG. 23  is a schematic illustrating a speed training regimen using the resistance exercise trainer. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As shown in the drawings for purposes of illustration, the present invention for a resistance exercise trainer is referred to generally by the reference number  10 . In general, the resistance exercise trainer  10  includes a bag  12 , a safe weight  14 , a belt  16  and a leash  18 . Accordingly, the bag  12 , the safe weight  14  (or multiple safe weights  14 ), the belt  16  and the leash  18  may be sold individually or provided as a kit and sold together as the resistance exercise trainer  10 . The resistance exercise trainer  10  is usable by both individuals as well as groups. Exercises associated with the resistance exercise trainer  10  may vary depending on use and the desired workout routine. For example, pulling the bag  12  having the safe weight  14  therein, when coupled to a person  20  via the belt  16  and the leash  18  ( FIG. 19 ), provides efficient, effective and proven resistance training. The resistance exercise trainer  10  and related speed training techniques appeal to both young and old athletes in, for example, primary schools, second schools, high schools, colleges, universities and professional athletics. Use of the resistance exercise trainer  10  allows such athletes to train without the risk of injury and other inconveniences of the aforementioned resistance devices provided in the prior art. 
     The bag  12  illustrated in  FIG. 2  is constructed of low density materials and is ideal for use with resistance exercises as an alternative to traditional resistance training devices disclosed in the prior art. The bag  12  is also ideal for use in resistance training and speed training programs. The bag  12  is preferably manufactured from any one of a variety of heavy duty materials such as reinforced vinyl, canvas, ballistic materials, rubber, mesh, Kevlar, carbon or other similar materials of comparable strength and durability. The exterior of the bag  12  preferably includes a rigid rubber or vinyl material capable of sliding on grass or synthetic turf while being pulled behind an individual during running or walking. The bag  12  is constructed for optimum durability and is manufactured to be dragged on the ground, a track, a gym floor, on natural grass, on synthetic turf, on ice, through sand, through snow and over most all terrains. The bag  12  may be dragged on a generally planar front surface  22 , a generally planar back surface  24  or even a bottom surface  26 , as each of the surfaces  22 ,  24 ,  26  are made from the same rigid rubber or vinyl material. Moreover, the tear-drop shape of the bag  12 , as shown best in  FIG. 19 , allows the bag  12  to be dragged along either the front surface  22  or the back surface  24 , which are symmetrical to one another. 
     The bag  12  is assembled by connecting a mesh webbing  28  between opposite sides of the front surface  22  and the back surface  24 . The mesh webbing  28  preferably comprises an extremely durable material having the capacity to stretch. Such materials may include neoprene, gorilla mesh, netting, rubber, webbing or other similar strong materials. The mesh webbing  28  is able to stretch to accommodate multiple safe weights  14  disposed within the interior of the bag  12 . The mesh webbing  28  is not necessarily manufactured out of the materials comprising the front surface  22  and the back surface  24  because the bag  12  is not meant to be dragged along the mesh webbing  28 . Accordingly, the mesh webbing  28  attaches to the surfaces  22 ,  24 ,  26  along a binding  30  that runs along the exterior of the surfaces  22 ,  24 ,  26  as shown in  FIG. 2 . The binding  30  also comprises a high-strength material resistant to wear during dragging and is therefore extremely durable. The mesh webbing  28  may be attached to the binding  30  by any means known in the art, including stitching. 
       FIG. 3  illustrates an alternative embodiment of the bag  12  including a reinforcement patch  32  that strengthens the mesh webbing  28 . The reinforcement patch  32  preferably comprises a composite material that is substantially resilient to wear and tear. Ideal materials include a fiber-reinforced composite material or another type of woven cloth-fiber filament. The reinforcement patch  32  is located in a corner of the bag  12 , as shown in  FIG. 3 , and may be stitched, double stitched or triple stitched into the front surface  22 , the back surface  24 , the bottom surface  26 , the mesh webbing  28  and/or into the binding  30 . The area of the mesh webbing  28  closest to the bottom surface  26  experiences the greatest amount of weight from the safe weights  14  when the bag  12  is dragged during resistance exercise training. The reinforcement patch  32  simply ensures that the stretchable mesh webbing  28  does not rip or otherwise tear away from the surfaces  22 ,  24 ,  26  or the binding  30 . Moreover, the reinforcement patch  32  may form a pocket with the mesh webbing  28 . A logo or other design may be attached to the reinforcement patch  32 . This may be particularly desirable for using the bag  12  in association with advertising campaigns. 
       FIG. 4  is an enlarged view of the front surface  22  of the bag  12 .  FIG. 4  further illustrates the contoured design of the outer surface  22 , which extends around the exterior of the bag  12  to both the back surface  24  and the bottom surface  26 . Each of the channels/ridges formed longitudinally along the surfaces  22 ,  24 ,  26  ensure that components of the bag  12  do not interfere or obstruct sliding movement thereof during use of the resistance exercise trainer  10  as shown in  FIG. 19 . The longitudinal nature also ensures that the bag  12  does not become hooked or caught on obstructions on the ground that may have a tendency to jerk the bag  12  to a stop. When this design is combined with the aforementioned rubber and/or vinyl material, the bag  12  easily slides upon any desired surface and the resistance is most closely associated with the quantity of the safe weights  14  within the interior of the bag  12 . 
     The perspective view in  FIG. 5  illustrates opening the bag  12  by separating a pair of tapered sections  34  disposed generally above the mesh webbing  28 . The mesh webbing  28  terminates just below the tapered sections  34  that, when separated, provide access to the interior of the bag  12 . A portion of the mesh webbing  28  may fold upon itself, as shown, to ensure that the bag  12  remains shut when carrying one or more of the safe weights  14 . An elastic band  36  may reinforce the mesh webbing  28  and effectively draw opposite sides of the bag  12  toward one another. Of course, the elastic band  36  stretches so the bag  12  may accommodate numerous items, including multiple safe weights  14 . A pair of handles  38  and a pair of extensions  40  looped to retain a pair of O-rings  42  are located along the interior of the bag  12 . The handles  38  and the extensions  40  attach to the interior of the bag  12  so none of the components thereof interfere with pulling the bag  12  in accordance with the embodiments disclosed herein. The handles  38  and the extensions  40  are preferably double stitched or triple stitched to the bag  12  to remain securely attached thereto. The stitching should be capable of withstanding at least one hundred pounds of weight resultant from filling the bag  12  with a plurality of the safe weights  14 . For example, a user must be able to pick up the bag  12  with the handles  38  to transport the components of the resistance exercise trainer  10 , including up to one hundred pounds of the safe weights  14 . Moreover, the extensions  40  should also be capable of remaining attached to the bag  12  when a user pulls the bag  12 . In this regard, the extensions  40  may experience greater tensional forces than the handles  38  when the user starts pulling the bag  12  from an initial resting position. The extensions  40  may also experience increased tensional forces when the bag  12  encounters additional surface friction or becomes unexpectedly snagged on an object on the ground when being pulled by the user. 
       FIG. 6  is a side view of the bag  12  having each of the tapered sections  34  withdrawn from one another such that a user may access the internal compartment of the bag  12 . As shown, the elastic band  36  stretches along with the mesh webbing  28  to allow the user to access the inside of the bag  12 . When the bag  12  is open, a user may access the handles  38 , in order to transport the bag  12 , any safe weights  14  residing therein, the extensions  40  and/or the O-rings  42 . The height of the bag  12  is preferably sized to also receive the belt  16  and/or the leash  18  so the bag  12  can transport all of the components of the resistance exercise trainer  10 . In this embodiment, the bag  12  stores the safe weights  14 , the belt  16  and the leash  18 , all which may be transported together through use of the handles  38 .  FIG. 7  more specifically illustrates a hand  44  grasping each of the handles  38  to transport the bag  12  and any components therein. 
       FIG. 8  is a partially cut-out perspective view further illustrating the inside of the bag  12 .  FIG. 9  similarly shows a cross-sectional view of the inside of the bag  12 . As shown in both  FIGS. 9 and 10 , the bag  12  includes a pair of straps  46  at least partially sewn into the interior of the bag  12 . The straps  46  are designed to engage one another and to securely retain the safe weights  14 . For example, the straps  46  may be stitched or removably attached to one or more sections of the interior of the bag  12 . The straps  46  should securely attach to the bag  12  to ensure retainment of the one or more safe weights  14  therein, especially when performing training exercises with the resistance exercise trainer  10 . In one embodiment, the straps  46  are double or triple stitched to the interior, in the same or similar manner as are the handles  38  and/or the extensions  40 . One of the straps  46  includes a tri-glide  48  looped or otherwise threaded into the corresponding strap  46 . The other strap  46  has an engagement end  50  that threadingly secures to the tri-glide  48 . A person of ordinary skill in the art will readily recognize that each of the straps  46  may selectively engage one another by one or more mechanisms known in the art. In one example, the tri-glide  48  and the engagement end  50  are replaced by complementary strips that include hook and loop fasteners, buttons, snaps, etc. In a preferred embodiment, the straps  46 , which may include the tri-glide  48  and the engagement end  50 , are preferably adjustable such that a user may tighten or loosen the straps  46  depending on the quantity of the safe weights  14  in the interior of the bag  12 . The tri-glide  48  is particularly useful in this embodiment because the user may thread more or less material of the strap  46  having the engagement end  50  through the tri-glide  48  to lengthen or shorten the encompassing nature of the straps  46  around the safe weights  14 . 
       FIGS. 10 and 11  are cross-sectional views of the bag  12  illustrating placement ( FIG. 10 ) and retention ( FIG. 11 ) of a plurality of the safe weights  14  within the interior of the bag  12 . As briefly described above, the mesh webbing  28  is capable of stretching to accommodate one or more of the safe weights  14  placed within the bag  12 . The bag  12  is designed to hold at least one safe weight  14  and is preferably sized to hold up to ten of the safe weights  14 .  FIGS. 10  and  11  are not drawn to scale in this regard. A person of ordinary skill in the art will readily recognize that the size of the bag  12  may be bigger or smaller depending on the size and/or desired quantity of the safe weights  14  to be held in the bag  12  for purposes of using the resistance exercise trainer  10 . In a particularly preferred embodiment, each of the safe weights  14  weigh ten pounds. A user may therefore add weight to the bag  12  in increments of ten pounds (e.g. 10, 20, 30, 40, 50 or 60 pounds, etc.). Accordingly, the bag  12  should easily accommodate up to, but not limited by, at least ten of the ten pound safe weights  14 , thereby aggregating to one hundred pounds of weight when the bag  12  is full. Hence, the material comprising the front surface  22  and the back surface  24  must be able to withstand being dragged across grass, synthetic turf or other terrains and/or surfaces having at least one hundred pounds of weight placed therein. An individual may drag the bag  12 , as described below, while walking, running, skating or during any other training regimen designed to increase speed, strength or agility. Pulling the bag  12  is one aspect of the resistance exercise trainer  10  that teaches resistance training to build endurance and speed. The bag  12  may be manufactured in various sizes such that additional safe weights  14  may be placed therein to increase the overall weight to well over one hundred pounds (e.g. two hundred pounds). 
     More specifically with respect to  FIG. 10 , each safe weight  14  is inserted into the interior of the bag  12  diagonally as generally shown in phantom. At least partial diagonal insertion of the safe weight  14  is required as a result of the stretchable mesh webbing  28  and the elastic band  36  that generally endeavors to close the sides of the bag  12 . Of course, the mesh webbing  28  and the elastic band  36  easily stretch to accommodate insertion of the safe weight  14  for snug retention therein. Each of the safe weights  14  comfortably reside within the interior of the bag  12  as shown in  FIG. 11 . After the user inserts the desired quantity of the safe weights  14  (e.g. four safe weights  14  in  FIG. 11 ), each of the safe weights  14  are secured through use of the aforementioned straps  46 . For example, the engagement end  50  of one of the straps  46  is threaded through the tri-glide  48  of the opposite strap  46 . The straps  46  are tightened to the uppermost of the safe weights  14  by pulling the engagement end  50  taut through the tri-glide  48 . The additional material of the strap  46  extending from the tri-glide  48  to the engagement end  50  may be threaded back through the tri-glide  48  and used to retain additional safe weights  14 . For example, a user may endeavor to insert a fifth safe weight  14  into the interior of the bag  12  such that the strap  46  having the engagement end  50  needs loosening to accommodate the additional width of the fifth safe weight  14 .  FIG. 11  also illustrates that the hand  44  may comfortably extend into the interior of the bag  12  to engage each of the handles  38 . This enables the user to carry the bag  12  or perform exercises with the bag  12  in accordance with the resistance exercise trainer  10 . Moreover, the gap between the fourth safe weight  14  and the handles  38  may be used to house the belt  16  and/or the leash  18  if the user endeavors to transport the resistance exercise trainer  10  from one location to another. This feature is also particularly desirable to keep each of the components of the resistance exercise trainer  10  together during non-use. 
       FIG. 12  illustrates the safe weight  14  removed from the bag  12 . The safe weights  14  are low impact weights primarily designed to be loaded and hauled in the bag  12  for resistance training purposes. The safe weight  14  may also be grabbed by the person  20  in the manner shown in  FIGS. 21 and 23 . The safe weight  14  preferably includes a handgrip  52  to enable the person  20  to grasp the safe weight  14  in the manner shown in  FIG. 23 . The handgrip  52  increases the versatility of the safe weight  14  and the quantity of exercises that may be performed by the person  20 . This enables the person  20  to use the safe weight  14  to work various muscles in the body during weight training. The person  20  in  FIG. 21  is performing triceps exercises while the person  20  in  FIG. 23  is performing biceps exercises.  FIG. 13  illustrates a cross-sectional view of the safe weight  14  and the positioning of the handgrip  52  relative to a top surface  54  thereof. The handgrip  52  is stitched to the top surface  54  by any of the aforementioned stitching means. Preferably, a gap  56  is created between the top surface  54  and the handgrip  52  that enables the person  20  to slide the hand  44  therebetween (e.g.  FIG. 23 ). Accordingly, the hand  44  of the person  20  should snugly fit into the gap  56  such that the safe weight  14  may be held securely and symmetrically. The hand  44  may clench somewhat to grasp the safe weight  14 . The pressure applied to a plurality of dry granules  58  (or pellets) therein enables the person  20  to slightly reposition the fingers to permit a solid, molded fit to the palm of the hand of the person  20 . The safe weights  14  could also be filled with other low or no-impact material such as water or gel. 
     In one embodiment, the safe weights  14  are pre-bagged with ten pounds of the dry granules  58  packaged in thick heat-sealed poly-bags designed to prevent accidental spillage of the contents therein. The dry granules  58  may also comprise pellets or other low-density beads known in the art. The filled poly-bag weights are then inserted into a strong material bag manufactured from reinforced vinyl, canvas, ballistic material, etc. The handgrip  52  is stitched to the top surface  54  of the material bag to allow convenient handling or gripping while performing an exercise regimen, as described above. The poly-bag may also be filled with any quantity of the granules  58  to vary the weight of the safe weight  14 . Accordingly, the resistance exercise trainer  10  may be sold in a kit that has a plurality of the safe weights  14  that are the same weight (e.g. 10 lbs.) or include various weights. For example, the safe weights  14  may be specifically manufactured to retain two, five, ten or twenty pounds of the granules  58 . The choice of using the dry granules  58  as opposed to sand is to lessen the density of the load in the safe weight  14 . Sand can retain moisture and thereafter “cake”, which makes the sand denser and adds water weight. The dry granules  58  refrain from caking, clumping and/or retaining additional moisture. Thus, if the safe weight  14  is accidentally dropped, e.g. on a foot, the dry granules  58  are capable of dispersing at the point of impact (lowering the density thereof) thereby substantially reducing the risk of injury due to such accidents. 
       FIG. 14  illustrates an alternative embodiment of the safe weight  14  having the handgrip  52  stitched to the top surface  54  thereof. In this embodiment, the safe weight  14  includes a selectively sealable sleeve  60  that enables a user to fill or empty the granules  58  into or out from the interior of the safe weight  14 . The process for filling and sealing the safe weight  14  is generally shown in  FIGS. 15-18 . A person of ordinary skill in the art will readily recognize that the safe weight  14  may be emptied through a reverse procedure with respect to the embodiments described in  FIGS. 15-18 .  FIG. 15  illustrates an embodiment wherein the sleeve  60  is open and receiving the granules  58  therethrough. Once the safe weight  14  is filled with the granules  58  to approximately the sleeve  60 , each side of the sleeve  60  is moved inwardly so a pair of the internal sealers  62  can engage one another to seal off the interior of the safe weight  14  in the manner shown in  FIG. 16 . The internal sealers  62  may include any mechanism known in the art for attaching one side of the sleeve  60  to the other, such as zippers. Preferably, the internal sealers  62  provide a water and air tight seal to prevent any of the granules  58  from escaping from within the interior of the safe weight  14 . When the safe weight  14  is filled with sand, it is important that the internal sealers  62  lock out water or moisture to ensure that the sand does not “cake” or otherwise retain water weight. It is especially important that the internal sealers  62  are water tight when the safe weight  14  is filled with water. Two sets of the internal sealers  62  are shown with respect to  FIGS. 15-18 , but a person of ordinary skill in the art will readily recognize that multiple sets of internal sealers  62  may be used with the safe weight  14  depending on the desired application. For example, additional internal sealers  62  may be needed in the event that the safe weight  14  can retain more than ten pounds of weight, and less internal sealers  62  may be required if the safe weight  14  holds less than ten pounds of weight. 
     The sleeve  60  also includes a pair of external sealers  64 . The sleeve  60  is long enough such that it may fold upon itself wherein one external sealer  64  may engage the other external sealer  64 , as shown along the directional arrow in  FIG. 16 . This feature further ensures that the contents of the safe weight  14  remain securely retained therein. By bending the sleeve  60  to engage the external sealers  64 , the granules  58 , in the preferred embodiment, are essentially choked off from disengaging both of the internal sealers  62 . This is particularly preferred as the size and weight of the safe weight  14  may cause significant pressure and stress along the surface where the internal sealers  62  are located to connect opposite sides of the sleeve  60 . The external sealers  64  may comprise a set of complementary hook and loop fasteners, buttons, snaps or other clips for retaining a portion of the sleeve  60  to itself at an approximate ninety degree angle. The seal formed by the external sealers  64  does not necessarily need to be water or air tight as this desirable characteristic is already being performed by the internal sealers  62 . Without the external sealers  64 , disconnection of the internal sealers  62  may otherwise cause immediate loss of the contents of the safe weight  14 . This is particularly undesirable when the safe weight  14  is retaining the dry granules  58 . Moreover, the sleeve  60  may fold over and attach to a bottom surface  66  of the safe weight  14  as shown generally in  FIG. 17  and more specifically shown in  FIG. 18 . In this regard, the sleeve  60  is configured to double and triple seal the granules  58  within the enclosure of the safe weight  14 . To accomplish this, the sleeve  60  further includes a body sealer  68  that folds over and engages a similar body sealer  68  attached to the bottom surface  66  of the safe weight  14 . The body sealers  68  retain the sleeve  60  along the exterior of the safe weight  14 . This ensures that the fillable safe weight  14  shown in  FIGS. 15-18  retains a substantially contoured shape (best shown in  FIG. 17 ) similar to that of the safe weight  14  illustrated in  FIGS. 12-13 . The triple seal of the sleeve  60  is best shown in the enlarged view of  FIG. 18 . The body sealers  68  may further be used to prevent any of the contents, e.g. the granules  58 , from escaping out from within the interior of the safe weight  14 . The body sealers  68  do not necessarily form a water tight or air tight seal, but may include any of the sealing mechanisms described above with respect to the internal sealers  62  or the external sealers  64 . 
       FIG. 19  illustrates the bag  12  connected to the person  20  via the leash  18  and the belt  16 . The leash  18  is preferably manufactured from a webbing material (e.g. poly-webbing), stretchable materials, cable, nylon, elastic, heavy duty strap, bungee, rope (e.g. woven rope), plastic coated cable or other similar materials capable of removably connecting the leash  18  to both the belt  16  and the bag  12 . At one end, the leash  18  may connect to the bag  12  with a snap hook, O-ring, carabiner, or other various clips capable of connecting into grommets, O-rings or D-rings. For example,  FIG. 2  illustrates the bag  12  having the O-rings  42  mounted to corresponding ends of the extensions  40 . The O-rings  42  are preferably the only part of the bag  12  that is somewhat externally accessible during use. The leash  18  may be connected to the bag  12  through grommets set into the bag  12  in hard tooling leather that includes, but is not limited to, vegetable tan leather. Alternatively, the leash  18  could also be connected to the bag  12  by running the leash  18  through an oblong grommet or through the O-rings  42 . A person of ordinary skill in the art will readily recognize that there are many ways to removably yet securely attach the leash  18  to the bag  12  so the person  20  may pull the bag  12  in accordance with  FIG. 19 . 
     On the other end, the leash  18  connects to the belt  16  through O-rings, D-rings, tri-clips, tri-glides or heavy duty Velcro triple sewn onto the belt  16 . For example, the leash  18  may fold over and attach to a tri-glide for the purpose of keeping excess leash material or slack from interfering with the person  20  during use. The tri-glide also allows the person  20  to adjust the length of the leash  18  depending on the size of the person  20 . In this regard, taller persons would preferably lengthen the leash  18  and shorter persons may endeavor to shorten the length of the leash  18 . Moreover, other small hardware may also removably connect the leash  18  to the belt  16 . Less preferably, the leash  18  may be permanently stitched to the belt  16 . 
     In another alternative embodiment, the leash  18  may removably attach to the belt  16  via a release mechanism  72 .  FIG. 20  illustrates the person  20  accessing the release mechanism  72  integrated into the back portion of the belt  16 . The release mechanism  72  generally includes a disengagement member  74  that selectively attaches to an engagement member  76  integrated into one end of the leash  18 . Accordingly, the engagement member  76  may selectively disengage the disengagement member  74  on-the-fly during use of the resistance exercise trainer  10 . For example, the person  20  starts by dragging the bag  12  as shown in  FIG. 19 . At some point, the person  20  selectively accesses the release mechanism  72 , and specifically the disengagement member  74 , to disconnect the leash  18  and the bag  12  from the belt  16 . The release mechanism  72  may comprise a snap, hook, lever, U-lock or another mechanical or adhesive mechanism that enables the person  20  to easily disconnect the disengagement member  74  from the engagement member  76  on-the-fly. The release mechanism  72  may also be integrated into the belt  16  such that the person  20  may hold or access a portion of the release mechanism  72  in a more convenient location than the lower back area of the person  20 . In this embodiment, the person  20  may pull a lever or string-type mechanism integrated into the front side of the belt  16  that causes the disengagement member  74  to release the engagement member  76 . The release mechanism  72  may be particularly desirable for speed burst training and other agility, speed or dexterity training. 
     The belt  16  is best illustrated in  FIG. 1  and is preferably made from a strong webbing material capable of withstanding high resistances due to weights in the bag  12  and motion by the person  20  ( FIGS. 19 and 20 ). The belt  16  is preferably easily adjustable among a wide range of sizes and may easily strap to a number of individuals having various waist sizes. The belt  16  adjusts by folding one end of the belt  16  over and through a buckle  70  ( FIGS. 19 and 20 ). Excess portions of the belt  16  may attach to itself with a complementary strip of hooks and loops, such as Velcro. The buckle  70  may be manufactured from a rigid material such as metal or plastic to ensure durability. The belt  16  could also comprise one of multiple harnesses capable of connecting the leash  18  at the back of the belt  16 . Such a harness may attach around the shoulders (e.g. a shoulder strap), upper torso or another portion of the upper body of the person  20 . This allows the person  20  to use the resistance exercise trainer  10  while walking, running, climbing, swimming, skating or while performing other speed and endurance training exercises or regimens. Moreover, the belt  16  should be manufactured from a material and have a width capable of withstanding curling around the torso of the person  20  while pulling the bag  12  and the corresponding safe weights  14 . Any one of these different embodiments are suitable to perform the related speed training exercises associated with the resistance exercise trainer  10 . 
       FIG. 19  illustrates one preferred use of the resistance exercise trainer  10 . As shown, the person  20  is dragging the bag  12  along a surface  78 . The person  20  is wearing the belt  16  and is coupled to the bag  12  via the leash  18 , as described above. The person  20  experiences resistance from the bag  12  when running. The weight of the bag  12 , which includes the safe weights  14 , drags along the surface  78  and exerts a resistive force as the person  20  endeavors to move the bag  12  in the direction shown generally in  FIG. 19 . The resistance exercise trainer  10  enables the person  20  or multiple individuals or teams, to simultaneously drag the bag  12  containing one or more safe weights  14  for safe and effective resistance in speed training. If the person  20  falls while running or is accidentally hit by another bag  12  having one or more safe weights  14  therein, the impact or collision therebetween is harmless. Colliding with or otherwise impacting a traditional metal sled can be extremely harmful and can cause injury to one or more persons. This is particularly detrimental for individuals or a player on a team. Another important aspect of the resistance exercise trainer  10  is that the bag  12  immediately ceases moving after the person  20  stops pulling the bag  12 . The bag  12  stops because either the front surface  22  or the back surface  24  is fully engaged against the ground surface  78 . The friction between the front surface  22  or the back surface  24  and the ground surface  78 , in conjunction with the granulars  58  in the safe weight  14 , causes the momentum of the bag  12  to immediately stop when the person  20  stops exerting a force thereon. Momentum associated with traditional sleds or skids allows the devices to continue moving, even after sudden stops, as the entire weight of the sled typically rests on two metal bars. Hence, the overall construction and fabrication of the components making up the resistance exercise trainer  10  are particularly safer in view of the prior art and do not comprise high density materials such as metals, woods, hard plastics, fiberglass, etc. that can injure an athlete. 
     The leash  18  is also extremely versatile and has multiple uses in association with the resistance exercise trainer  10 .  FIG. 1  illustrates the leash  18  disconnected from the bag  12  and the belt  16  and substantially coiled. The versatility of the leash  18  allows it to be folded upon itself for easy and compact storage. The compact nature of the leash  18  also enables a user to store or transport the leash  18  in the interior of the bag  12 , as described above.  FIG. 22  illustrates a particularly preferred use for the leash  18  in accordance with the corresponding speed training process of the resistance exercise trainer  10 . Here, the leash  18  is used as a jump rope. The person  20  may use the leash  18  as a jump rope as a solitary exercise or in conjunction with an exercise regimen as described below with respect to the speed training triangle. The length of the leash  18  should also be adjustable to better accommodate the height of the person using the leash  18  as a jump rope. 
       FIG. 23  illustrates using the resistance exercise trainer  10  in three separate stages called the speed training triangle. In one aspect, the person  20  may use the safe weight  14  in weight lifting exercises. As shown in  FIG. 23 , the person  20  uses the safe weight  14  as a hand-held weight. Here, the person  20  exercises arm muscles by performing curls, shoulder presses, tricep extensions or bench presses that work the pectorals and other arm muscles. The construction of the safe weight  14  as described above eliminates the risk of harm due to accidental impact of the safe weight  14  on the body of the person  20 . In another aspect of the speed training triangle, the person  20  uses the leash  18  as a jump rope, as described above with respect to  FIG. 21 . Jumping rope is particularly desirable for increasing endurance. Lastly, the person  20  may use the resistance exercise trainer  10  in resistance training exercises as described and shown in  FIGS. 19 and 20  above. The speed training triangle was developed to complement the bag  12  and the safe weights  14  such that the person  20  has the ability to train and concentrate on increased speed and endurance with one resistance exercise trainer  10 . Moreover, the resistance exercise trainer  10  is particularly suited for individuals as the bag  12 , the safe weight  14 , the belt  16  and the leash  18  are compact and easily storable. For instance, twenty-four of the safe weights  14  take up the space of a traditional metal sled. 
     Although several embodiments have been described in detail for purposes of illustration, various modifications may be made to each without departing from the scope and spirit of the invention. Accordingly, the invention is not to be limited, except as by the appended claims.