Take a look at a few of the pictures below to see some of the Cy-Falls Baseball Players utilizing a slosh pipe to strengthen not just their legs but their arms, shoulders, and entire core.
A slosh pipe is basically a 9 or 10 foot PVC pipe filled 2/3 of the way with water and only weighs 30-40 lbs, but makes any exercise harder as athletes now have to stabilize their entire body to keep the pipe balanced while still performing the exercise.
Holding a slosh pipe in a Zercher postion (as seen in the picture), or an even bigger challenge overhead, turns any exercise into a full body exercise forcing the arms, shoulders, core, upper back and lower back to resist tipping while the water shifts while trying to produce power into the ground off a single leg (especially during lunges).
They can be used instead of barbells or dumbbells for nearly any exercise and by swapping them out you will achieve a different type of strength that works in any situation.
Give a slosh pipe a try if you really want to add another dimension to your sports training and let me know how it goes.