Abstract: A spring exerciser, including a case, a pull strap, and a rewinding mechanism having a supporting shaft and a rewinding hub rotatably sleeving the supporting shaft; the rewinding hub includes an inner cavity and a winding groove; a torsion spring is installed in the inner cavity; two ends of the torsion spring are hooked to the supporting shaft and to the rewinding hub respectively; the pull strap includes a middle portion positioned in the inner cavity, a first end portion, and a second end portion; the first end portion passes through the inner cavity and winds around the winding groove; the second end portion also passes through the inner cavity and winds around the winding groove; the first end portion and the second end portion wind in the winding groove to form layers of winding coils defined alternately by the first end portion and the second end portion.

Abstract: A hula hoop, comprising a hoop body which includes a plurality of unit sections connected end to end, two adjacent unit sections are detachably connected to each other through a connecting member, and each unit section has an accommodating groove for inserting the connecting member. The front section and the rear section of the connecting member are inserted into the accommodating grooves of two adjacent unit sections, and the unit section has a locking mechanism for keeping the connecting member in the accommodating groove. The hoop body comprises a plurality of unit sections connected end to end. Two adjacent unit sections are connected to each other through a connecting member, which can realize the rapid disassembly and assembly of the unit sections.

Abstract: Quick assembly and disassembly connecting structures and a weight adjustable dumbbell; each connecting structure include a male structure and a female structure respectively on its two sides; the male structure includes a plug-in part; the female structure includes an insertion groove, a lock button and lock button restoring springs; during assembly, the plug-in part of a connecting structure inserts into the insertion groove of another connecting structure; a lock button of said another connecting structure abuts a top side of the plug-in part to prevent it from falling out; when pushing the lock button away from the plug-in part, the lock button is separable from the insertion groove, and stops abutting the top side of the plug-in part to make it separable; the lock button restoring springs biases the lock button towards the plug-in part and resets the lock button towards the plug-in part when external force is not applied.

Abstract: A hula hoop, comprising a hoop body which includes a plurality of unit sections connected end to end, two adjacent unit sections are detachably connected to each other through a connecting member, and each unit section has an accommodating groove for inserting the connecting member. The front section and the rear section of the connecting member are inserted into the accommodating grooves of two adjacent unit sections, and the unit section has a locking mechanism for keeping the connecting member in the accommodating groove. The hoop body comprises a plurality of unit sections connected end to end. Two adjacent unit sections are connected to each other through a connecting member, which can realize the rapid disassembhly and assembly of the unit sections.