Jumping capacity is an expression of explosive strength in the form of a jump. Other expressions of explosive strength include martial arts kicks and punches, or the action of the arm in javelin.
The larger the force an athlete can apply in the short time of contact with the ground or in the time it takes to throw a martial arts kick or punch, the greater is their explosive strength.
The basis of training for jumping ability also apply to any explosive strength training.
Explosive strength can be enhanced by very fast movements against resistance. These movements can be strength exercises such as barbell squats (although must be very fast!), medicine ball throws, kettlebell swings, Olympic lifts, jumps and plyometrics.
An athlete’s first step to enhance explosive strength may be to increase maximal strength by standard strength exercises. To decide where to begin, these questions have to be answered –
1) Is the athlete’s maximal strength much lower than that of other athletes who demonstrate sufficient explosive strength in their sport?
2) Is the height of the athletes countermovement jump less than that of other athletes in their sport who jump well and squat the same as the athlete?
Improvements of maximal strength up to a point may increase the amount of force the athlete can execute within a timeframe of 0.15-0.18 of a second (the window of opportunity for most sports).
Eventually an athlete’s maximal strength increases so much that all the force increase happens later than the time available for action. From that moment, the key to improvement lies in performing explosive strength exercises.
Both jumps and fast squats enhance explosive strength and both types of actions should be used in training. Fast squats are less demanding and put less stress on the body than full force jumps and therefore should form the bulk of an athletes training.
Two principles should be applied in selecting jumping or plyometric exercises – their likeness to movements in the sport and their difficulty.
