A rebounding device includes a front member, a rear member, and a spring mechanism including a first biasing element and force adjustment assembly. The force adjustment assembly includes a spring element including a front planar surface and a rear planar surface connected at a rounded portion, wherein the front planar surface contacts an inner surface of the front member; a screw housing secured to an inner surface of the rear member, wherein the screw housing includes a longitudinal channel and a bore on an upper surface; a drive screw positioned through the bore and along the longitudinal channel of the screw housing; a threaded block positioned within the longitudinal channel of the screw housing, wherein the threaded block is configured to move vertically along the longitudinal channel, and wherein the rear planar surface of the spring element is secured to the threaded block.

A rebounding device includes a front member, a rear member, and a spring mechanism including a first biasing element and force adjustment assembly. The force adjustment assembly includes a spring element including a front planar surface and a rear planar surface connected at a rounded portion, wherein the front planar surface contacts an inner surface of the front member; a screw housing secured to an inner surface of the rear member, wherein the screw housing includes a longitudinal channel and a bore on an upper surface; a drive screw positioned through the bore and along the longitudinal channel of the screw housing; a threaded block positioned within the longitudinal channel of the screw housing, wherein the threaded block is configured to move vertically along the longitudinal channel, and wherein the rear planar surface of the spring element is secured to the threaded block.

A rebounding device includes a front member, a rear member, and a spring mechanism including a first biasing element and force adjustment assembly. The force adjustment assembly includes a spring element including a front planar surface and a rear planar surface connected at a rounded portion, wherein the front planar surface contacts an inner surface of the front member; a screw housing secured to an inner surface of the rear member, wherein the screw housing includes a longitudinal channel and a bore on an upper surface; a drive screw positioned through the bore and along the longitudinal channel of the screw housing; a threaded block positioned within the longitudinal channel of the screw housing, wherein the threaded block is configured to move vertically along the longitudinal channel, and wherein the rear planar surface of the spring element is secured to the threaded block.

A tongue strengthening device includes an intraoral bolus simulator having a sensor input component. An extraoral user interface is connected to the intraoral bolus. The intraoral bolus simulator is moveable relative to the extraoral user interface in response to a movement of a user's tongue. The sensor input component is configured to detect a pressure or force applied to the intraoral bolus simulator and/or to detect movement of the intraoral bolus simulator relative to the extraoral user interface.

A fitness stool includes a sliding system, a support and connection frame and an elastic device. One end of the sliding system is inserted into and fixed to the ground of the earth and the other end of the sliding system is connected with the support and connection frame. The support and connection frame can be moved upwards and downwards relative to the ground, and the sliding system comprises a sliding rod and a sliding cavity. The elastic device realizes elastic damping and elastic return between the ground and the support and connection frame.

A fitness stool includes a sliding system, a support and connection frame and an elastic device. One end of the sliding system is inserted into and fixed to the ground of the earth and the other end of the sliding system is connected with the support and connection frame. The support and connection frame can be moved upwards and downwards relative to the ground, and the sliding system comprises a sliding rod and a sliding cavity. The elastic device realizes elastic damping and elastic return between the ground and the support and connection frame.

An adjustable resistance exercise machine for providing variable resistance forces on a pull cable extending from the machine. The adjustable resistance exercise machine generally includes a plurality of power springs that may be selectively engaged using an adjustment mechanism. By engaging springs with different forces, the resistance may be adjusted incrementally as preferred for performing different exercises. The adjustable resistance exercise machine may be connected to various structures, either below or above an exerciser, to allow the exerciser to choose whether to pull the pull cable up or down during exercise.

An adjustable resistance exercise machine for providing variable resistance forces on a pull cable extending from the machine. The adjustable resistance exercise machine generally includes a plurality of power springs that may be selectively engaged using an adjustment mechanism. By engaging springs with different forces, the resistance may be adjusted incrementally as preferred for performing different exercises. The adjustable resistance exercise machine may be connected to various structures, either below or above an exerciser, to allow the exerciser to choose whether to pull the pull cable up or down during exercise.

A fitness training apparatus is described that can include at least one pole, at least one set of one or more adjustable members, and at least one elastic member. The at least one pole can be configured to extend from at least one vicinity of at least one shoulder of a user to another at least one vicinity of a waist of the user. The at least one set of one or more adjustable members can be adjustably coupled to the at least one pole. The at least one elastic member can be configured to be adjustably coupled to the at least one set of one or more adjustable members. Related methods, techniques, articles, systems, and apparatuses are also described.

A fitness training apparatus is described that can include at least one pole, at least one set of one or more adjustable members, and at least one elastic member. The at least one pole can be configured to extend from at least one vicinity of at least one shoulder of a user to another at least one vicinity of a waist of the user. The at least one set of one or more adjustable members can be adjustably coupled to the at least one pole. The at least one elastic member can be configured to be adjustably coupled to the at least one set of one or more adjustable members. Related methods, techniques, articles, systems, and apparatuses are also described.