Athlete education is important on multiple levels when it comes to training, yet many are clueless about what and why they are training the way they are. This could be for many reasons. Many athletes just want to put their heads down and train as long as it makes them better and makes them feel like they did something. Even if this is the case, it is important for athletes to at least have a general idea of what and why they are doing something. Another possibility is that the coach does not know why they are doing something other than they saw someone else do it. If this is the case, the coach cannot explain to the athlete why they are performing an exercise, and the athlete (and parent) education gets put on the back burner.
In the strength and conditioning/fitness world, there are many similar terms that get interchanged when they don't actually mean the same thing. Depth and drop jumps are one of those instances where people interchange the two terms when they are different yet very similar exercises used for different outcomes. A drop jump is technically a branch of depth jumping with different mechanics and adaptation goals. Both are used to train the stretch-shortening cycle but with different goals in mind.
It should also be stated that these are high-level plyometrics, and some exposure to less intense plyos and a strength program should be incorporated before jumping straight into these movements.
A depth jump is where an athlete starts on top of a platform of some kind, typically a box, and steps off, landing on the ground with a degree of knee flexion that is very similar to, if not the same, as the angle which the athlete finds themselves in a vertical jump. Then the athlete rebounds from the ground for maximal height. This exercise is all about maximal force output and getting to the highest point possible. With this in mind, some variables will be sacrificed. The athlete will have slower ground contact times compared to a drop jump. To achieve maximal height, focus on a target to reach for, such as a Vertec, really anything for the athlete to try and touch.
There are several common mistakes when implementing depth jumps into a training session. First is performing too many repetitions in a single session. Depth jumps are a maximal effort exercise, so, therefore, should be trained by completing a smaller number of reps with plenty of rest so full recovery can be achieved with little fatigue. That leads to the second common mistake, not enough rest between reps. If the goal of performing depth jumps is maximal power output, then the athlete must be able to maximally jump. If they are fatigued from previous reps, they will not be able to do this. Another common fault is starting from a point that is either too low or too high for the particular athlete. If the starting point is too low, there will not be an adequate amount of overload to obtain the desired adaption in the stretch-shortening cycle. If the starting point is too high, the opposite is true. The elastic properties of the athlete can be over-overloaded, resulting in a less than maximal rebound.
A drop jump is technically a kind of depth jump just with different goals in mind for adaptation, so therefore different mechanics when performing the movement. The drop jump is characterized by falling off a box and rebounding with very quick ground contact times and minimal knee bend, focusing on muscular and tendon stiffness. This will result in lower jump heights, but that is not necessarily the goal of performing drop jumps. When landing during a drop jump, the foot should be rigid, ready to pop back up into the air. This can be done either by landing on the ball of the foot or with a flat foot. The drop jump is started off of a much shorter box than the depth jump because of the need for quick ground contact times, around 8 to 24 inches depending on the athlete.
The Key Differences
So, when deciding which type of jump is best for you or your athletes, keep the outcome goal in mind. Depth jumps are used for maximal power output and achieving maximal height. Typically, they are associated with a deeper knee bend (closely related to a standing vertical jump) and longer ground contact times. With depth jumps, athletes will start on higher boxes, and landing mechanics may also be slightly compromised with exceptionally tall boxes. Also, the anatomy used to create force is different between the two movements. With the depth jump, force production is dictated more by the hips, knees, ankles, and slightly by the arm swing.
With drop jumps, the purpose is rebounding from the ground very quickly with maximum muscle and tendon stiffness. This requires quick ground contact times and minimal knee bend. Drop height will also be shorter than for a depth jump and, again, should be appropriate for the athlete to achieve the training goal. As stated before, the drop jump is a submaximal plyometric in terms of power output. Therefore, multiple reps can be strung together as fatigue is less of a factor for these.
Both of these exercises can be helpful for athletes looking to increase general explosiveness but should be used based on the athletes' needs and the needs of the sport they play. For instance, a sprinter that has slower ground contact times may benefit more from a drop jump, whereas a basketball player that lacks jump height may benefit more from a depth jump. However, in both of these situations, the athletes could benefit from both exercises. The sprinter in terms of maximal force put into the ground on contact when sprinting (depth jump) and the basketball player could benefit from drop jumps as the sport also requires multiple jump attempts (say from a rebound that continually gets tipped) where the fastest jumper, not necessarily the highest jumper may get the ball. Look at the athlete. Look at the sport. Decide what fits best with the situation in front of you.
Depth jumps are typically programmed with a very small amount of reps per set, 1-3, with plenty of rest between reps (if using a multiple rep set) and even more rest between sets. Drop jumps can be programmed with more reps strung together since they are submaximal, and the goal is to improve consecutive ground contacts in whatever form that may be. The volume of jumps is determined by where the athlete is in their training cycle and what they are doing outside of the strength/ plyometric training program.
There are many terms in the strength and conditioning/ fitness industry that get incorrectly interchanged, confusing athletes, and sometimes the coaches themselves. Depth and drop jumps are just one of those scenarios, although they are similar. Depth jumps are a maximal power output movement that requires a deeper knee bend and therefore longer ground contact times and requires full rest between sets and reps to limit fatigue. Drop jumps are a submaximal jump with minimal knee bend and quick ground contact times for a faster rebound off of the ground. They don't require as long of rest periods between sets and reps since they are a submaximal jump. Both exercises can be used to enhance athletic ability but in slightly different ways. Take into account the needs of the athlete and the needs of the sport(s) they play and decide what makes the most sense.