SPB looks at new research on the benefits of plyometrics for increased lower-limb stiffness, and how to construct an effective plyometrics program MORE
The drop depth jump: a plyometric exercise to increase vertical leap and improve jumping ability
The depth jump is a plyometric exercise. Plyometric exercises work on the principle that a concentric muscular contraction is much stronger if it immediately follows an eccentric contraction of the same muscle. (Eccentric muscular action occurs when a muscle lengthens under load – eg the lowering phase of a biceps curl. Concentric muscular contraction occurs when a muscle shortens under load.)
The effect of a plyometric exercise is a bit like stretching out a coiled spring to its fullest extent (the eccentric contraction), then letting it go (the concentric contraction); large amounts of energy are released in a split second as the spring recoils.
General – The depth jump provides a great base of dynamic power for the majority of sports. This is because it closely matches the sport specific speeds of movement and muscular action. Most standard weight training lifts, even when performed as quickly as possible, take 0.5-0.7 seconds to complete, whereas during a depth jump your feet may only be in contact with the ground for between 0.2 and 0.3 seconds.
Sport specific – Although the basic depth jump is very sports specific in itself, it can be made even more so by adaptation and variation (more later).
Stand on top of a strong platform 0.5-0.8m high (the greater the height, the greater the strength component, the lower the height the greater the speed component).
- Step slightly forward off the platform. Land toward your forefeet;
- React as quickly as possible to the ground and spring immediately back up into the air;
- Use your arms to add to your speed by drawing them back prior to stepping off the platform and swinging them vigorously upward as your feet hit the ground;
- Keep your back in neutral alignment, ie not arched or rounded;
- Focus your gaze straight ahead of you.
In the air
- Maintain neutral posture and a balanced elevated chest position throughout the exercise. Do not attempt to absorb the landing on impact, rather react as quickly and as fast as you can, even if this sacrifices height gained;
- The faster a muscle is forced to perform an eccentric contraction, the greater the concentric force it can generate. To help your understanding: think of a rubber ball being thrown against a wall. What happens when the ball is thrown harder? It springs back even faster and further. This is the effect you are looking for when performing plyometric exercises, like the depth jump;
- Always warm up thoroughly before performing depth jumps;
- Don’t perform more than two workouts a week and allow at least five days before important competitions;
- Monitor the number of jumps performed. Depth jump volume is measured in ground contacts; avoid more than 60 in a session. Start with 3 x 6 repetitions;
- To allow your power-producing fast-twitch muscle fibres to be at their most effective, take 30 seconds recovery between exercises and two minutes between sets;
- Perform depth jumps on a non-slip flat surface – a sprung gymnasium floor or an all-weather athletics track are ideal surfaces;
- You need to be in ‘the right frame of mind’ to get the most out of depth jumping. Going through the motions will not turn on sufficient neuromuscular input to optimise their performance.
Sport specific exercise progression
Single-leg depth jump (hop) for distance
This variation will up your leg muscles’ power and is a great exercise for field and racket sports players, sprinters and jumpers (where all movements are performed with an independent leg action). Note the single-leg depth jump places greater potential strain on the legs and back, as such this exercise should only be performed by those with a high degree of prior plyometric training experience.
Assume the same starting position as for the first exercise, but this time drive forward to land about 1m in front of the platform, on the same leg. React as quickly as possible to the ground and hop forward as far as you can. Maintain an upright posture and cycle your hopping leg under your body whilst in the air. Coordinate your arms with your legs, ie in a running, ‘opposite arm to leg’ style. Try 3 x 5 repetitions, alternating left and right leg sets.
John Shepherd MA is a specialist health, sport and fitness writer and a former international long jumper