Pretty straight forward, this one – get fifteen rugby players, split them in half feeling somewhat bad for the poor guy that has to get cut up the middle since it’s an odd number, and make one half do resistance sprints. For anyone unsure, resistance sprints are generally done with a sled tied behind the runner, or a parachute. After six weeks of two-a-week sessions, assess results. And they found that resistance sprinting improves a few parameters actually, including acceleration and jumping strength/height. This style of training is no secret to sprinters and footballers, but doesn’t seem to get much press in other sports where acceleration is a huge benefit such as soccer. The bottom line is that if you’re involved in a sport where you need to be fast on your feet, include sprints and resistance sprints in your workouts.

Source: Harrison AJ, Bourke G. The effect of resisted sprint training on speed and strength performance in male rugby players. J Strength Cond Res. 2009 Jan;23(1):275-83.