A bat includes a handle having a proximate end and a distal end, a barrel having a hollow portion that accommodates the distal end, and a first damping section at least partially sandwiched between the handle and the barrel in the interior of the hollow portion. The first damping section includes a first portion in contact with each of the handle and the barrel in the interior of the hollow portion, and a second portion disposed closer to the proximate end than the first portion, the second portion being in contact with an inner peripheral surface of the barrel and not being in contact with an outer peripheral surface of the handle. In a cross section along a center axis of the barrel, the barrel has a depression depressed relative to the inner peripheral surface in the cross section, the second portion has a protrusion fitted in the depression.

A bat includes a handle having a proximate end and a distal end, a barrel having a hollow portion that accommodates the distal end, and a first damping section at least partially sandwiched between the handle and the barrel in the interior of the hollow portion. The first damping section includes a first portion in contact with each of the handle and the barrel in the interior of the hollow portion, and a second portion disposed closer to the proximate end than the first portion, the second portion being in contact with an inner peripheral surface of the barrel and not being in contact with an outer peripheral surface of the handle. In a cross section along a center axis of the barrel, the barrel has a depression depressed relative to the inner peripheral surface in the cross section, the second portion has a protrusion fitted in the depression.

A bat includes a handle having a proximate end and a distal end, a barrel having a hollow portion that accommodates the distal end, and a first damping section at least partially sandwiched between the handle and the barrel in the interior of the hollow portion. The material of the first damping section has a D hardness of 60 or more, a loss coefficient tan δ of 0.11 or more as determined under conditions of a temperature of 20° C., a frequency of 150 Hz, and the amount of strain 3000 μST, and a loss coefficient tan δ of 0.09 or more as determined under conditions of a temperature of 20° C., a frequency of 500 Hz, and the amount of strain 3000 μST.

A bat includes a handle having a proximate end and a distal end, a barrel having a hollow portion that accommodates the distal end, and a first damping section at least partially sandwiched between the handle and the barrel in the interior of the hollow portion. The material of the first damping section has a D hardness of 60 or more, a loss coefficient tan δ of 0.11 or more as determined under conditions of a temperature of 20° C., a frequency of 150 Hz, and the amount of strain 3000 μST, and a loss coefficient tan δ of 0.09 or more as determined under conditions of a temperature of 20° C., a frequency of 500 Hz, and the amount of strain 3000 μST.

An underwater training apparatus is disclosed. The underwater training apparatus may include a barrel. The barrel may contain a plurality of holes disposed across the barrel. Each of the holes of the barrel may pass through a wall of the barrel. The underwater training apparatus may also include a base funnel. The base funnel may contain a plurality of holes disposed across the base funnel. Each of the holes of the base funnel may pass through a wall of the base funnel. The underwater training apparatus may also include a handle. The handle may mechanically couple the barrel and the base funnel.

An underwater training apparatus is disclosed. The underwater training apparatus may include a barrel. The barrel may contain a plurality of holes disposed across the barrel. Each of the holes of the barrel may pass through a wall of the barrel. The underwater training apparatus may also include a base funnel. The base funnel may contain a plurality of holes disposed across the base funnel. Each of the holes of the base funnel may pass through a wall of the base funnel. The underwater training apparatus may also include a handle. The handle may mechanically couple the barrel and the base funnel.

An active suspension orthotic support system is disclosed. The suspension orthotic support system comprises at least one variable resistance beam extending from a heel section to a mid-arch section of the footwear, wherein rotation of the variable resistance beam from a first position to a second position causes a resistance provided by the variable resistance beam to vary between a minimum resistance to a maximum resistance.

An active suspension orthotic support system is disclosed. The suspension orthotic support system comprises at least one variable resistance beam extending from a heel section to a mid-arch section of the footwear, wherein rotation of the variable resistance beam from a first position to a second position causes a resistance provided by the variable resistance beam to vary between a minimum resistance to a maximum resistance.

A bat, which has a hollow barrel and an internal assembly configured to resist deformation of the hollow barrel, is disclosed. The internal assembly includes multiple rods disposed longitudinally within the hollow barrel. The internal assembly can include a deformable ring having a substantially circular outer wall having a diameter less than an inner diameter of the hollow barrel and multiple holes, with each hole configured to at least partially receive a rod of the multiple rods. The bat can have an end cap including end cap holes extending partially through the end cap, with each end cap hole configured to at least partially receive a rod.

A knob sleeve assembly for a ball bat extending along a longitudinal axis and having a tubular handle portion and a knob attached the handle portion. The knob sleeve assembly includes a plurality of annular bodies formed of a resilient material. Each of the bodies defines a central opening for receiving the handle portion of the bat. Each of the bodies has an annular body height within the range of 0.25 to 1.0 inch, and a maximum annular body outer diameter within the range of 1 to 3 inches. The plurality of annular bodies varies from one another according to at least one annular body characteristic. The knob sleeve characteristic is selected from the group consisting of annular body height, maximum annular body outer diameter, weight, color, material durometer value, annular body draft angle and combinations thereof.