Plyometrics, also known as "jump training" or "plyos", is a method of developing explosive power. This training focuses on maximum force in short intervals of time.

The original version of plyometrics was defined as the shock method. It was created by Russian scientist Yuri Verkhoshansky in late 1960s for the Russia Olympic team. This seemingly exotic method was thought to be responsible for the growing superiority of Eastern European athletes in many sports. The term "plyometrics" was first used in 1975 by American track and field coach Fred Wilt after he studied Dr. Verkoshansky’s training methods.

The second version of plyometrics relates to doing any form of jump regardless of execution time. Such jumps cannot be considered truly plyometric (as described by Verkhoshansky) since their intensity is much lower and the time of muscle contraction is much greater.

Explosive or true plyometrics (shock method)

In these exercises a muscle should be stretched a little by a powerfull external force for a very short time, and immediately contract in a very fast explosive way as fast as possible. For example in Depth Jumps an athlete jumps (or rather falls) down from a box. When he hits the ground, the impact force stretches his leg muscles, and the athlete must immediately jump as high or as far as possible. The jumping must be initiated immediately upon landing, not after. This keeps the ground contact very short, 0.2 - 0.3 seconds.

Caution: true plyometrics are high-impact, and depth jumps are very high-impact exercises. Only well-prepared athletes should do depth jumps. Wathen suggests this minimum strength level for depth jumps: free‐weight squat 1.5 times body weight and/or squat 60% of body weight five times within five seconds. In Russian elite teams an athlete was cleared for depth jumps if he had 4 years of weight training experience, was able to squat 1.5 times his body weight and was at least 18 years old so that growth plates had fused.

Exercise progressions

These progressions suggest exercises from easiest to hardest. Move to the harder exercise when you master the easier one. As a general rule, start with a single-repetition lower impact exercises with a self-check and reset of the posture at each landing. Next - do these exercises without resetting: jump, land, pause, repeat. Progress to multiple jumps. Shock exercises like depth jumps are at the very end of the progression.

Depth Jumps progression

1: Pogo, Squat Jump (single), Box Jump

2: Squat Jumps (multiple), Knee­Tuck Jump, Scissors Jump

3: Depth Jumps

Bounds and Skips progression

1: Prancing, Galloping, Fast Skipping

2: Stair Jumps, Lateral Stair Bound, Alternate Leg Bound

3: Box Jumps

Hops progression

1: Double-Leg Hop (single)

2: Hurdle Jumps