Abstract:
Liquid-containing weighted device usable on land and/or in water and suitable for use in fitness, training, conditioning and/or rehabilitation. According to one embodiment, the device may include a closed receptacle, at least a portion of which may be transparent or translucent to permit a user to view its contents. The receptacle may be partially filled with a mixture of a liquid, such as water, and one or more insoluble solid materials, such as glitter and/or gravel. The mixture, when in motion, creates an inertia that provides an undertow reaction to assist with reverse movements to reduce or to eliminate kinetic joint load. In addition, as the mixture is in motion, the gravel scrapes against the inner surface of the receptacle, thereby enabling the device to create a rhythmic sound when being used, which may enhance its usability when a user is exercising to music.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Patent Application No. 61/757,572, filed Jan. 28, 2013, the disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates generally to liquid-containing weighted devices of the type suitable for use in one or more of fitness, training, conditioning and rehabilitation and relates more particularly to a novel such liquid-containing weighted device. 
         [0003]    In U.S. Pat. No. 5,393,285, inventors Fischer, Sr. et al., which issued Feb. 28, 1995, and which is incorporated herein by reference, there is disclosed a liquid-containing weighted exercise device. The liquid-containing weighted exercise device of the aforementioned patent is a low-impact exercise device. According to one embodiment, which embodiment is designed for two-handed use, the exercise device comprises a rigid body comprising an elongated cylinder having a side wall and opposed end walls. The exercise device also comprises a pair of end caps attached at the end walls of the rigid body and further comprises a pair of handle elements, each handle element being attached to an outer surface of an end cap. A weight adjusting cavity may be defined by an end cap. The end cap may further comprise a cover removably attachable to secure a weight adjusting element within the cavity. The outer surfaces of the end caps are convex surfaces, and the handle element comprises a strap adapted for adjustable attachment across a user&#39;s hand gripped upon the convex surface of the end cap. 
         [0004]    According to another embodiment disclosed in the aforementioned patent, which embodiment is designed for one-handed use, the exercise device comprises a rigid body comprising an elongated arcuate member having a side wall, a first end and a second end. The device also comprises handle means comprising an elongated handle end cap member extending between the first and second ends and defining a handle surface. Preferably, a weight adjusting cavity is defined by the handle end cap member, which further comprises a cover removably attachable to secure a weight adjusting element within the weight adjusting cavity. 
       SUMMARY OF THE INVENTION 
       [0005]    It is an object of the present invention to provide a novel liquid-containing weighted device. 
         [0006]    It is another object of the present invention to provide a novel liquid-containing weighted device that is suitable for use in one or more of fitness, training, conditioning and rehabilitation. 
         [0007]    According to one aspect of the invention, there is provided a liquid-containing weighted device that comprises (a) a closed receptacle, the closed receptacle having a volume; and (b) a mixture disposed within the closed receptacle, the mixture occupying less than the entirety of the volume of the closed receptacle, the mixture comprising a liquid and one or more types of solids that are insoluble in the liquid, wherein at least one type of solid of the one or more types of solids produces an audible sound against the closed receptacle when the liquid-containing weighted device is moved. 
         [0008]    In a preferred feature of the invention, at least one type of solid of the one or more types of solids comprises a quantity of gravel. 
         [0009]    In another preferred feature of the invention, at least a portion of the closed receptacle may be one of translucent and transparent. 
         [0010]    In another preferred feature of the invention, the mixture may occupy about 40% to about 50% of the volume of the closed receptacle. 
         [0011]    In another preferred feature of the invention, the liquid may comprise water. 
         [0012]    In another preferred feature of the invention, the at least one or more types of solids may further comprise a light-reflective and/or light-dispersive material. 
         [0013]    In another preferred feature of the invention, the closed receptacle may be generally spherical. 
         [0014]    In another preferred feature of the invention, the closed receptacle may be generally cylindrical. 
         [0015]    In another preferred feature of the invention, the closed receptacle may be generally kettlebell-shaped. 
         [0016]    According to another aspect of the invention, there is provided a liquid-containing weighted device that comprises (a) a first closed receptacle, the first closed receptacle having a volume; (b) a mass disposed within the first closed receptacle, the mass occupying less than the entirety of the volume of the first closed receptacle, the mass comprising a liquid; and (c) a bar, the bar having a first end and a second end, the first closed receptacle being coupled to the first end of the bar. 
         [0017]    In a preferred feature of the invention, the liquid-containing weighted device may further comprise a wrist strap, the wrist strap being coupled to the bar proximate to the second end. 
         [0018]    In another preferred feature of the invention, the mass may further comprise at least one of a first type of solid and a second type of solid, the first type of solid comprising a material that produces an audible sound against the first closed receptacle when the liquid-containing weighted device is moved and the second type of solid comprising a light-reflective and/or light-dispersive material. For illustrative purposes only, the first type of solid material may be gravel, and the second type of solid material may be glitter. 
         [0019]    In another preferred feature of the invention, the first closed receptacle may be removably coupled to the first end of the bar. 
         [0020]    In another preferred feature of the invention, the first closed receptacle may be generally spherical. 
         [0021]    In another preferred feature of the invention, the first closed receptacle may be generally cylindrical. 
         [0022]    In another preferred feature of the invention, the first closed receptacle may be generally kettlebell-shaped. 
         [0023]    In another preferred feature of the invention, the liquid-containing weighted device may further comprise a second closed receptacle having a volume and a mass disposed within the second closed receptacle, the second closed receptacle being coupled to the second end of the bar. 
         [0024]    According to yet another aspect of the invention, there is provided a liquid-containing weighted device that comprises (a) a pair of closed receptacles, each of the pair of closed receptacles having a volume; (b) a mass disposed within each of the closed receptacles, the mass occupying less than the entirety of the volume of each of the closed receptacles, the mass comprising a liquid; and (c) a bar, the bar having a first end and a second end, one of the closed receptacles being coupled to the first end of the bar, the other of the closed receptacles being coupled to the second end of the bar. 
         [0025]    In a preferred feature of the invention, the closed receptacles may be generally spherical. 
         [0026]    In another preferred feature of the invention, the closed receptacles may be generally cylindrical. 
         [0027]    In another preferred feature of the invention, the closed receptacles may be generally kettlebell-shaped. 
         [0028]    In another preferred feature of the invention, the mass may further comprise at least one of a first type of solid and a second type of solid, the first type of solid comprising a material that produces an audible sound against the closed receptacle when the liquid-containing weighted device is moved and the second type of solid comprising a light-reflective and/or light-dispersive material. 
         [0029]    For illustrative purposes only, the first type of solid material may be gravel, and the second type of solid material may be glitter. 
         [0030]    In another preferred feature of the invention, each of the closed receptacles may be removably coupled to the bar. 
         [0031]    In another preferred feature of the invention, the liquid-containing weighted device may further comprise a first collar and a second collar, wherein one of the closed receptacles may be secured to the first collar and the other of the closed receptacles may be secured to the second collar, and wherein the first end of the bar may be screwed to the first collar and the second end of the bar may be screwed to the second collar. 
         [0032]    According to yet another aspect of the invention, there is provided a liquid-containing weighted device that comprises (a) a weighted object; (b) a second weighted object; and (c) a bar, the bar being reversibly connectable to each of the first weighted object and the second weighted object; (d) wherein each of the first and second weighted objects has an integrally-formed handle. 
         [0033]    In another preferred feature of the invention, each of the first weighted object and the second weighted object may comprise a closed receptacle and a mass disposed within the closed receptacle, the mass occupying less than the entirety of the volume of the closed receptacle, the mass comprising a liquid. 
         [0034]    In another preferred feature of the invention, the mass may further comprise at least one of a first solid that is insoluble in the liquid and a second solid that is insoluble in the liquid, the first solid producing an audible sound against the closed receptacle when the liquid-containing weighted device is moved, the second solid being light-reflective and/or light dispersive. 
         [0035]    Additional objects, as well as features and advantages, of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice of the invention. In the description, reference is made to the accompanying drawings which form a part thereof and in which is shown by way of illustration various embodiments for practicing the invention. The embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0036]    The accompanying drawings, which are hereby incorporated into and constitute a part of this specification, illustrate various embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings wherein like reference numerals represent like parts: 
           [0037]      FIG. 1(   a ) is a side view of a first embodiment of a liquid-containing weighted device suitable for use in one or more of fitness, training, conditioning and rehabilitation, the device being constructed according to the teachings of the present invention; 
           [0038]      FIG. 1(   b ) is an enlarged fragmentary longitudinal section view of the device of  FIG. 1(   a ), with the contents of the receptacle not being shown; 
           [0039]      FIGS. 2(   a ) through  2 ( e ) are diagrammatic sequential views showing the device of  FIGS. 1(   a ) and  1 ( b ) used as a training device for golf; 
           [0040]      FIG. 3  is a side view of a second embodiment of a liquid-containing weighted device suitable for use in one or more of fitness, training, conditioning and rehabilitation, the device being constructed according to the teachings of the present invention; 
           [0041]      FIGS. 4(   a ) through  4 ( e ) are diagrammatic views showing the device of  FIG. 3  used as a training device for tennis (serves, ground strokes, sweeps, backhands, and rotator warm-ups, respectively); 
           [0042]      FIG. 5(   a ) is a side view of a third embodiment of a liquid-containing weighted device suitable for use in one or more of fitness, training, conditioning and rehabilitation, the device being constructed according to the teachings of the present invention; 
           [0043]      FIG. 5(   b ) is an enlarged fragmentary longitudinal section view of the device of  FIG. 5(   a ), with the contents of the receptacles not being shown; 
           [0044]      FIGS. 6(   a ) through  6 ( f ) are diagrammatic views of various exemplary exercises (e.g., presses, rows, spinal twists and upper back strengtheners, simple torso twists, lat flies, and bicep curls, respectively) that may be performed using the device of  FIGS. 5(   a ) and  5 ( b ); 
           [0045]      FIG. 7  is a side view of a fourth embodiment of a liquid-containing weighted device suitable for use in one or more of fitness, training, conditioning and rehabilitation, the device being constructed according to the teachings of the present invention; 
           [0046]      FIG. 8(   a ) through  8 ( c ) are diagrammatic views of various exemplary exercises (e.g., walking pumps, jogging, and scissor twists, respectively) that may be performed using the device of  FIG. 7 ; 
           [0047]      FIGS. 8(   d ) through  8 ( f ) are diagrammatic sequential views showing the device of  FIG. 7  used to perform a lunge with curl and press exercise; 
           [0048]      FIG. 9  is a side view of a fifth embodiment of a liquid-containing weighted device suitable for use in one or more of fitness, training, conditioning and rehabilitation, the device being constructed according to the teachings of the present invention; 
           [0049]      FIG. 10  is a side view of a sixth embodiment of a liquid-containing weighted device suitable for use in one or more of fitness, training, conditioning and rehabilitation, the device being constructed according to the teachings of the present invention; 
           [0050]      FIGS. 11(   a ) through  11 ( e ) are diagrammatic views of various exemplary exercises (e.g., pumps, swingers, scissors, stretches, and rotation warm-ups, respectively) that may be performed using the device of  FIG. 10 ; 
           [0051]      FIG. 12  is a side view of a seventh embodiment of a liquid-containing weighted device suitable for use in one or more of fitness, training, conditioning and rehabilitation, the device being constructed according to the teachings of the present invention; and 
           [0052]      FIGS. 13(   a ) through  13 ( f ) are diagrammatic views of various exemplary exercises (e.g., sways, figure eights, presses, sitting rainbows, squats, and twists, respectively) that may be performed using the device of  FIG. 12 . 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0053]    Referring now to  FIGS. 1(   a ) and  1 ( b ), there are shown side and enlarged fragmentary longitudinal section views, respectively, of a first embodiment of a liquid-containing weighted device suitable for use in one or more of fitness, training, conditioning and rehabilitation, the device being constructed according to the teachings of the present invention and being represented generally by reference numeral  11 . 
         [0054]    Device  11  may comprise a receptacle  13 , a mass  15 , a collar  17 , a bar  19 , and a wrist strap  21 . 
         [0055]    Receptacle  13  may be a generally spherical member made of a lightweight yet durable material, such as, but not limited to, a blow-molded polyvinyl chloride or a similarly suitable material. At least a portion of receptacle  13  may be sufficiently translucent or transparent so that the contents of receptacle  13  may be viewed, for example, by the user of device  11  while device  11  is being used. In the present embodiment, receptacle  13  may have a diameter of about 6 inches; however, it can readily be appreciated that the diameter of receptacle  13  may be greater than or less than 6 inches without departing from the present invention. 
         [0056]    It should be understood that, although receptacle  13  of device  11  is disclosed herein as being spherical, receptacle  13  need not be spherical and may take other shapes. 
         [0057]    Mass  15 , which may be disposed within receptacle  13 , may comprise a mixture of a liquid  23  and at least one type of solid that is insoluble in liquid  23 . According to one embodiment, liquid  23  may comprise water and may preferably comprise distilled water. The distilled water may contain an aquamarine colorant or other similar agent for inhibiting murkiness of liquid  23 . The at least one insoluble solid may comprise a light-reflective and/or light-dispersive material  25 . Examples of the light-reflective and/or light-dispersive material  25  may comprise glitter, MYLAR® polyester film particles and/or foil particles. Alternatively or additionally, the at least one insoluble solid may comprise a noise-producing material  26  of the type that may generate an audible scraping or scratching sound against receptacle  13  when device  11  is in use. For purposes of the present specification and claims, an audible scraping or scratching sound is defined to mean a sound that is audible to the unaided ear of the user, i.e., without requiring the use of a sound magnifying or enhancing device, during the ordinary use of device  11 . Examples of the noise-producing material  26  may comprise, but are not limited to, gravel, such as colored or uncolored gravel. Due to presence of noise-producing material  26 , device  11  can be used like a percussion instrument, such as a maraca, to enhance a user&#39;s experience, such as, for example, when moving device  11  in sync with music. Mass  15  may further comprise other components, such as soluble or dispersible colorants and/or soluble or dispersible thickeners, and/or may further comprise a second liquid, which may or may not be miscible with the first liquid. 
         [0058]    Preferably, the volume of mass  15  is less than the available internal volume of receptacle  13  and more preferably, the volume of mass  15  is about 40% to about 50% of the available internal volume of receptacle  13 . 
         [0059]    Mass  15  may be introduced into receptacle  13  through an opening (not shown). Such an opening may be sealed with a patch, which may be made of the same material as receptacle  13 , after mass  15  has been loaded into receptacle  13 . The introduction of mass  15  into said opening of receptacle  13  and the sealing of said opening may take place prior to the coupling of receptacle  13  to collar  17 . 
         [0060]    Collar  17 , which may be a unitary member made of a molded polymer, may comprise a concave surface  27  that is appropriately shaped to receive receptacle  13 . Preferably, receptacle  13  is bonded to concave surface  27  with a suitable bonding agent (not shown), which may be, for example, an epoxy. Opposite to concave surface  27 , collar  17  may be further shaped to include an internally-threaded bore  28 , which preferably terminates prior to concave surface  27 . Said internally-threaded bore may be used to threadingly receive an externally-threaded end  29  of bar  19 . 
         [0061]    Bar  19  may comprise an elongated member, which may be a solid rod or a hollow tube. Examples of suitable materials for bar  19  may include, for example, a wood dowel or a lightweight metal rod, such as an aluminum rod. In the present embodiment, bar  19  may have a length of approximately 12 inches; however, it can readily be appreciated that the length of bar  19  may be greater than or less than 12 inches without departing from the present invention. A wrap  31 , which may be, for example, an ethylene vinyl acetate foam wrap, may be provided around a portion of bar  19  to cushion bar  19 , to improve its grip and/or to waterproof bar  19 . An end  33  of bar  19  may be enlarged to retain wrist strap  21 , which may be, for example, a vinyl strap adapted to slip around a user&#39;s wrist. In the present embodiment, strap  21  may have a length of approximately 5 inches; however, it can readily be appreciated that the length of strap  21  may be greater than or less than 5 inches without departing from the present invention. 
         [0062]    Device  11  may have a weight of, for example, approximately 3 lbs. Depending on the volume of mass  15  within receptacle  13 , device  11  may be buoyant. It should be appreciated that bar  19  may be reversibly screwed into and unscrewed from collar  17 . In this manner, device  11  may be stored in a compacted state, with bar  19  unscrewed from collar  17 , or device  11  may be used without bar  19  attached to collar  17 . 
         [0063]    One or more devices  11  may be used, for example, on land and/or in water and may be used, for example, to perform exercises of the type disclosed in U.S. Pat. No. 5,393,285. Alternatively, device  11  may be used, for example, as a training device for golf, as shown in  FIGS. 2(   a ) through  2 ( e ) of the present application. 
         [0064]    Referring now to  FIG. 3 , there is shown a side view of a second embodiment of a liquid-containing weighted device suitable for use in one or more of fitness, training, conditioning and rehabilitation, the device being constructed according to the teachings of the present invention and being represented generally by reference numeral  111 . 
         [0065]    Device  111  may be similar in many respects to device  11 , the principal differences between device  111  and device  11  being that device  111  may have a receptacle  113  of reduced diameter and a collar  117  of correspondingly reduced size, as compared to receptacle  13  and collar  17 . For example, receptacle  113  may have a 4-inch diameter, as opposed to an 6-inch diameter. Consequently, device  111  may have a weight of, for example, 2 lbs., as opposed to device  11 , which may have a weight of, for example, 3 lbs. 
         [0066]    One or more devices  111  may be used, for example, on land and/or in water and may be used, for example, to perform exercises of the type disclosed in U.S. Pat. No. 5,393,285. Alternatively, device  111  may be used, for example, as a training device for tennis, as shown in  FIGS. 4(   a ) through  4 ( e ) of the present application. 
         [0067]    Referring now to  FIGS. 5(   a ) and  5 ( b ), there are shown side and enlarged fragmentary longitudinal section views, respectively, of a third embodiment of a liquid-containing weighted device suitable for use in one or more of fitness, training, conditioning and rehabilitation, the device being constructed according to the teachings of the present invention and being represented generally by reference numeral  211 . 
         [0068]    Device  211  may comprise a pair of receptacles  213 - 1  and  213 - 2 , a pair of masses  215 - 1  and  215 - 2 , a pair of collars  217 - 1  and  217 - 2 , and a bar  219 . 
         [0069]    Each of receptacles  213 - 1  and  213 - 2  may be similar in shape to a kettlebell (but need not be kettlebell-shaped) and may be made of a lightweight yet durable material, such as, but not limited to, a blow-molded polyvinyl chloride or a similarly suitable material. At least a portion of each of receptacles  213 - 1  and  213 - 2  may be sufficiently translucent or transparent so that the contents of receptacles  213 - 1  and  213 - 2  may be viewed, for example, by the user of device  211  while device  211  is being used. 
         [0070]    A wrap  220 - 1 , which may be, for example, an ethylene vinyl acetate foam wrap, may be applied to an integrally-formed handle portion of receptacle  213 - 1 , and a wrap  220 - 2 , which may be an ethylene vinyl acetate foam wrap, may be applied to an integrally-formed handle portion of receptacle  213 - 2 . 
         [0071]    Mass  215 - 1  may be disposed within receptacle  213 - 1 , and mass  215 - 2  may be disposed within receptacle  213 - 2 . Each of masses  215 - 1  and  215 - 2  may comprise a mixture of a liquid  223  and at least one type of solid that is insoluble in liquid  223 . According to one embodiment, liquid  223  may comprise water and may preferably comprise distilled water. The distilled water may contain an aquamarine colorant or other similar agent for inhibiting murkiness of liquid  223 . The at least one insoluble solid may comprise a light-reflective and/or light-dispersive material  225 . Examples of the light-reflective and/or light-dispersive material  225  may comprise glitter, MYLAR® polyester film particles and/or foil particles. Alternatively or additionally, the at least one insoluble solid may comprise a noise-producing material  226  of the type that may generate an audible scraping or scratching sound against receptacles  213 - 1  and  213 - 2  when device  211  is in use. Examples of the noise-producing material  226  may comprise, but are not limited to, gravel, such as colored or uncolored gravel. Due to presence of noise-producing material  226 , device  211  can be used like a percussion instrument, such as a maraca, to enhance a user&#39;s experience, such as, for example, when moving device  211  in sync with music. Each of masses  215 - 1  and  215 - 2  may further comprise other components, such as soluble or dispersible colorants and/or soluble or dispersible thickeners, and/or may further comprise a second liquid, which may or may not be miscible with the first liquid. 
         [0072]    Preferably, the volumes of masses  215 - 1  and  215 - 2  are less than the available internal volumes of receptacles  213 - 1  and  213 - 2 , respectively. More preferably, the volumes of masses  215 - 1  and  215 - 2  are about 40% to about 50% of the available internal volumes of receptacles  213 - 1  and  213 - 2 , respectively. 
         [0073]    Masses  215 - 1  and  215 - 2  may be introduced into receptacles  213 - 1  and  213 - 2 , respectively, through an opening (not shown) in each of receptacles  213 - 1  and  213 - 2 . Each of said openings may be sealed with a patch, which may be made of the same material as receptacles  213 - 1  and  213 - 2 , after masses  215 - 1  and  215 - 2  have been loaded into receptacles  213 - 1  and  213 - 2 , respectively. The introduction of masses  215 - 1  and  215 - 2  into the openings of receptacles  213 - 1  and  213 - 2  and the sealing of said openings may take place prior to the coupling of receptacles  213 - 1  and  215 - 2  to collars  217 - 1  and  217 - 2 , respectively. 
         [0074]    Collars  217 - 1  and  271 - 2 , each of which may be a unitary member made of a molded polymer or another similarly suitable material, may comprise surfaces  227 - 1  and  227 - 2 , respectively, that are appropriately shaped to receive receptacles  213 - 1  and  213 - 2 , respectively. Preferably, receptacles  213 - 1  and  213 - 2  are bonded to surfaces  227 - 1  and  227 - 2  with a suitable bonding agent (not shown), which may be, for example, an epoxy. (It should be understood that, whereas collars  217 - 1  and  217 - 2  are shown in the present embodiment as abutting receptacles  213 - 1  and  213 - 2 , respectively, collars  217 - 1  and  217 - 2  could be appropriately shaped to receive the ends of receptacles  213 - 1  and  213 - 2 , respectively.) Opposite to surfaces  227 - 1  and  227 - 2 , collars  217 - 1  and  217 - 2  may be further shaped to include internally-threaded bores  218 - 1  and  218 - 2 , respectively, which preferably terminate prior to surfaces  227 - 1  and  227 - 2 , respectively. Said internally-threaded bores  218 - 1  and  218 - 2  may be used to threadingly receive externally-threaded ends  228 - 1  and  228 - 2  of bar  219 . 
         [0075]    Bar  219  may comprise an elongated member, which may be a solid rod or a hollow tube. Examples of suitable materials for bar  219  may include, for example, a wood dowel or a lightweight metal rod, such as an aluminum rod. In the present embodiment, bar  219  may have a length of, for example, approximately 14 inches. A wrap  230 , which may be, for example, an ethylene vinyl acetate foam wrap, may be provided around a portion of bar  219  to cushion bar  219 , to improve its grip and/or to waterproof bar  219 . 
         [0076]    Device  211  may have a weight of, for example, approximately 6 lbs, with receptacles each having a weight of 2.5 lbs and bar  219  having a weight of 1 lb. 
         [0077]    Depending on the volumes of masses  215 - 1  and  215 - 2  within receptacles  213 - 1  and  213 - 2 , respectively, device  211  may be buoyant. 
         [0078]    Device  211  may be used in at least two different modes. According to a first mode, bar  219  may be screwed into collars  217 - 1  and  217 - 2 , thereby coupling receptacles  213 - 1  and  213 - 2 . In this first mode, a user may hold device  211  by gripping bar  219  with one or two hands; alternatively, a user may hold device  211  by gripping receptacle  213 - 1  with one hand and by gripping receptacle  213 - 2  with the other hand. According to a second mode, bar  219  may be unscrewed from collars  217 - 1  and  217 - 2 , thereby decoupling receptacles  213 - 1  and  213 - 2 . Receptacle  213 - 1  may then be gripped in one hand, and receptacle  213 - 2  may be gripped in the other hand. One or more devices  211  may be used, for example, on land and/or in water and may be used, for example, to perform exercises of the type disclosed in U.S. Pat. No. 5,393,285 and/or the exercises shown in  FIGS. 6(   a ) through  6 ( f ) of the present application. 
         [0079]    Referring now to  FIG. 7 , there is shown a side view of a fourth embodiment of a liquid-containing weighted device suitable for use in one or more of fitness, training, conditioning and rehabilitation, the device being constructed according to the teachings of the present invention and being represented generally by reference numeral  311 . 
         [0080]    Device  311  may be similar in certain respects to device  211 . One difference between the two devices may be that, whereas device  211  may comprise receptacles  213 - 1  and  213 - 2 , which may have a kettlebell shape, device  311  may comprise receptacles  313 - 1  and  313 - 2 , which may be generally cylindrical in shape. Another difference between the two devices may be that a light-reflective coating  314 - 1  may be applied to a portion of receptacle  313 - 1  and that a light-reflective coating  314 - 2  may be applied to a portion of receptacle  313 - 2 . Coatings  314 - 1  and  314 - 2  may function as a safety feature to enable device  311  to be easily spotted by drivers when device  311  is being used by a person who is exercising, e.g., walking or running, in a street. Still another difference between devices  311  and  211  may be that device  311  may have a bar  319  (which may be covered or uncovered) that may be shorter than bar  219  of device  211 , for example, approximately 5 inches as opposed to approximately 14 inches, to enable facile one-handed use of device  311 . 
         [0081]    Device  311  may have a weight of, for example, about 1-2 lbs. 
         [0082]    One or more devices  311  may be used, for example, on land and/or in water and may be used, for example, to perform exercises of the type disclosed in U.S. Pat. No. 5,393,285 and/or the exercises shown in  FIGS. 8(   a ) through  8 ( f ) of the present application. 
         [0083]    Referring now to  FIG. 9 , there is shown a side view of a fifth embodiment of a liquid-containing weighted device suitable for use in one or more of fitness, training, conditioning and rehabilitation, the device being constructed according to the teachings of the present invention and being represented generally by reference numeral  411 . 
         [0084]    Device  411  may be similar in certain respects to device  311 . One difference between the two devices may be that, whereas device  311  may include receptacles  313 - 1  and  313 - 2 , which may be cylindrical in shape, device  411  may include receptacles  413 - 1  and  413 - 2 , which may be generally spherical in shape. 
         [0085]    Device  411  may be used in a fashion similar to that discussed above in connection with device  311 . 
         [0086]    Referring now to  FIG. 10 , there is shown a side view of a sixth embodiment of a liquid-containing weighted device constructed according to the teachings of the present invention, the device being represented generally by reference numeral  511 . 
         [0087]    Device  511  may be similar in certain respects to device  111 . One difference between the two devices may be that device  511  may have a bar  519  that may extend, for example, about 5 in. beyond collar  517 , as compared to bar  119  of device  111 , which may extend, for example, about 12 in beyond collar  117 . 
         [0088]    One or more devices  511  may be used, for example, on land and/or in water and may be used, for example, to perform exercises of the type disclosed in U.S. Pat. No. 5,393,285 and/or the exercises shown in  FIGS. 11(   a ) through  11 ( e ) of the present application. 
         [0089]    Referring now to  FIG. 12 , there is shown a side view of a seventh embodiment of a liquid-containing weighted device suitable for use in one or more of fitness, training, conditioning and rehabilitation, the device being constructed according to the teachings of the present invention and being represented generally by reference numeral  611 . 
         [0090]    Device  611  may comprise a receptacle  613 , a mass  615 , and a pair of end caps  617 - 1  and  617 - 2 . 
         [0091]    Receptacle  613  may be a generally cylindrical member, which may be made of a lightweight yet durable material, such as, but not limited to, a molded polyvinyl chloride or a similarly suitable material. At least a portion of receptacle  613  may be sufficiently translucent or transparent so that the contents of receptacle  613  may be viewed, for example, by the user of device  611  while device  611  is being used. In the present embodiment, receptacle  613  may have a diameter of about 5 in. and a length of about 12 in., with each of the ends (not shown) being externally-threaded for about 0.75 in.; however, it can readily be appreciated that the aforementioned dimensions of receptacle  613  may be varied without departing from the present invention. 
         [0092]    It should be understood that, although receptacle  613  of device  611  is disclosed herein as being cylindrical, receptacle  613  need not be cylindrical and may take other shapes. 
         [0093]    Mass  615 , which may be disposed within receptacle  613 , may comprise a mixture of a liquid  623  and at least one type of solid that is insoluble in liquid  623 . According to one embodiment, liquid  623  may comprise water and may preferably comprise distilled water. The distilled water may contain an aquamarine colorant or other similar agent for inhibiting murkiness of liquid  623 . The at least one insoluble solid may comprise a light-reflective and/or light-dispersive material  625 . Examples of the light-reflective and/or light-dispersive material  625  may comprise glitter, MYLAR® polyester film particles and/or foil particles. Alternatively or additionally, the at least one insoluble solid may comprise a noise-producing material  626  of the type that may generate an audible scraping or scratching sound against receptacle  613  when device  611  is in use. Examples of the noise-producing material  626  may comprise, but are not limited to, gravel, such as colored or uncolored gravel. Due to presence of noise-producing material  626 , device  611  can be used like a percussion instrument, such as a maraca, to enhance a user&#39;s experience, such as, for example, when moving device  611  in sync with music. Mass  615  may further comprise other components, such as soluble or dispersible colorants and/or soluble or dispersible thickeners, and/or may further comprise a second liquid, which may or may not be miscible with the first liquid. 
         [0094]    Preferably, the volume of mass  615  is less than the available internal volume of receptacle  613  and more preferably, the volume of mass  615  is about 40% to about 50% of the available internal volume of receptacle  613 . 
         [0095]    Mass  615  may be introduced into receptacle  613  through an opening (not shown). Such an opening may be sealed with a patch, which may be made of the same material as receptacle  613 , after mass  615  has been loaded into receptacle  613 . The introduction of mass  615  into said opening of receptacle  613  and the sealing of said opening may take place prior to the coupling of receptacle  613  to end caps  617 - 1  and  617 - 2 . 
         [0096]    End caps  617 - 1  and  617 - 2 , each of which may be a unitary member made of a lightweight yet durable material, such as a molded polymer or other similarly suitable material, may be internally threaded so that the ends of receptacle  613  can be screwed into end caps  617 - 1  and  617 - 2 . Handle straps  619 - 1  and  619 - 2  may be secured to end caps  617 - 1  and  617 - 2 , respectively. 
         [0097]    Device  611  may have a weight of, for example, approximately 3 lbs. Device  611  may be used, for example, on land and/or in water and may be used, for example, to perform exercises of the type disclosed in U.S. Pat. No. 5,393,285 and/or the exercises shown in  FIGS. 13(   a ) through  13 ( f ) of the present application. 
         [0098]    Without wishing to be limited to any particular theory behind the invention, it is believed that all of the embodiments disclosed herein provide a smooth resistance which automatically varies with the degree of effort applied. This method of operation is commonly referred to as “accommodating variable resistance” and is an effective method of providing low impact movement to the joints and muscles. 
         [0099]    The embodiments of the present invention recited herein are intended to be merely exemplary and those skilled in the art will be able to make numerous variations and modifications to it without departing from the spirit of the present invention. All such variations and modifications are intended to be within the scope of the present invention as defined by the claims appended hereto.