Box jumps however can be used year-round as a power development exercise due to the fact that the impact forces created when landing on a box are far less then those encounted when dropping off of a box.
EPTS athlete, and one of the top 50m freestyle swimmers in the country, Karl Krug uses many variations of box jumps on our dynamic effort training days to help build the power necessary to get him off the blocks and in the water as fast as possible. We use both jumps with a counter movement and jumps from a static, seated position. The latter being very beneficial for improving his start.
He has personal records of 47" with a countermovement and 45.5" from a static seated position.
Stay Strong & Healthy!