Many people think of golf as a relaxing, laid-back sport, but at the elite level, a golf swing is one of the most explosive, complex movements in any sport. Coach Jeremy Golden explains how to develop strength and power in golf athletes so that those physical improvements will correlate to a more efficient swing and a resulting longer drive.
By Joel Smith
I’m not big on pushing single training exercises, as too many athletes tend to search for the “magic pill” that will transform their athleticism. If one exercise might be close to an enchanted pharmaceutical for the vertical jump and explosive power, however, it would be the depth jump.
As a young athlete, I tried any training method I could get my hands on to improve my speed and jumping ability, as well as inventing many others. I tried high-repetition plyometric programs, ran stairs, did wall sits, basic strength training, and more. I acquired a few small gains here and there, but nothing dramatic. The search continued.
When I was 16, I found a plyometric program claiming to be more “science–oriented” in the back of a basketball magazine. Ordering that program altered the course of my athletic career—maybe even my life. The program was based, not on high-frequency plyometric exercises that were the flavor of the day, but rather on a low-frequency, high-intensity performance of a key exercise: the depth jump. I was sold hook, line, and sinker after reading the short manual and began my depth-jumping journey to a higher vertical jump and better athleticism.
Within two months of weekly high-intensity depth jump workouts, I found that not only had my jumping improved by around 5” (12cm) off both one- and two-leg styles of jumping (enough to score me a windmill dunk), but I was also faster and had increased speed and agility on the court. My track seasons also benefited, as I held the state lead in the high jump for several months during my senior year of high school.
All that being said, the depth jump is probably the most powerful exercise an athlete can utilize in terms of specific force overload. From Russian high jumping to cult sprint training methodology and commercial basketball performance programming, the depth jump is widely used.
The problem is that it is also the most misrepresented and misperformed exercise among many athletic populations. Much of this problem is due to a lack of understanding of the theory behind the depth jump, and what athletes are trying to accomplish in its performance!
Anatomy of the perfect depth jump
When it comes to training for any sport skill, specificity and overload are two principles you must have strongly in your corner. If you want to jump higher, something like jumps with a barbell on your back does a great job of overloading the jump pattern, but an external weight high on the spine will always cause more accessory recruitment than typical jumping. While having a barbell on one’s back is a nice way to overload, the brain reacts to this movement with a perception of a vertically raised center of mass, subtly altering jump biomechanics.
Weighted jumping (such as a weight vest) has its own shortcomings. Slapping weight on athletes and having them jump is great, but it tends to overload the “up” or concentric portion of the jump more than it does the “down” or eccentric portion—the portion of the jump where the greatest amount of energy is stored. This energy storage in the eccentric phase will largely determine the outcome of the jump.
With a need for eccentric strength in mind, enter the depth jump—an exercise that involves the following sequence:
- A drop from a box, bench, or elevated surface individualized for the strength or reactive component that is being trained, the current training intensity, and the individual plyometric ability of the athlete. The height of the box can be anywhere from 6” to 50,” and there is no magic number for any particular athlete. Rather, the height is determined by the ability of the athlete and the goal of the exercise.
- The initial drop off the box should typically be performed down at a 30-45 degree angle (not straight down in a 90-degree fall) to increase the contribution of the posterior chain of the jump, and promote some forward-moving reactivity. Variations of depth jumping may include lateral drops off the box with a straight fall and reaction, or jumps for distance off a box, which are taken into reactive jumps for distance.
- At the end of the drop, the athlete will hit the ground as softly as possible, and then reverse the movement into a jump upwards. The ground contact time present in the jump should be a reflection of the desired outcome of the movement, whether it is speed- or strength-oriented.
- The athlete will often, but not always, perform the jump upwards at a mirror angle of how they hit the ground. A common mistake is to jump straight up, perpendicular to the ground, as this again reduces the balance of forces present in the jump and puts too much strain on the quads and patellar tendon. From a biomechanical perspective, jumping straight up, rather than out, actually represents jumping backward more than jumping up.
- The upward jump after the initial landing should be maximal. This is the biggest transgression coaches commit against the plyometric gods. There are situations, such as early season training periods or working with developmental athletes, where maximal depth jumping may not be called for. In this case, I wouldn’t label the exercise “depth jumping.” To have a better maximal depth jump, outcome goals such as an overhead target or high collapsible hurdle should be used. We’ll get more into this in a bit. For now, here are videos of two types of outcome goal depth jumps that are performed correctly: the hurdle depth jump and target depth jump.
Video 1. Depth Jump with Target Object.
Video 2. Depth Jump Over Hurdle.
General guidelines for implementing depth jumps in a program
Now that we know what a good depth jump looks like, how and when do you implement them in a training program, and at what intensity?
First, when are athletes ready for depth jumps? Well, watching school children jump off various playground apparatuses would suggest that they might be good candidates, even if they aren’t squatting twice their bodyweight yet. In reality, there is a two-fold rationale for determining readiness for depth jumping in the program: training preparation and chronological age.
When people think of training preparation, they usually consider things like squat to bodyweight ratio, as well as aptitude in less intense plyometric activity. My answer to the preparation question is: If the athlete can absorb and react to the jump with good technique, there is no reason why a “strength deficit” should hold them back. Some athletes are just not designed to be strong in a deep squat. Personally, I’ve seen high jumpers in the 2.20m range who could barely squat their bodyweight, but could do any plyometric you asked. If you asked these athletes to achieve a 1.75x or 2.0x bodyweight squat before depth jumping, you would probably be waiting forever.
The second portion of readiness for depth jumps is the chronological argument. Just because an athlete can do depth jumps, does that mean they should? We’ll touch on this at the end of this article. Generally speaking, an athlete is best suited for depth jumps, at least the intense versions, after they have reached their peak height and are close to physical maturity. This isn’t so much for safety as it is for issues of long-term athletic development and the prevention of early intensification and peaking.
Now, the matter of intensity (drop height). It is the most immediate factor present in the movement, and the one most likely to influence the buy-in effect of the exercise due to the positive momentum of results from correct performance.
Using a too-high box will result in fear, high-stress landings, and potential injury. A “safe” box height for any athlete, regardless of the training goal, is one in which they land and then:
- Stick the landing for several seconds, in the case of a depth landing, if needed.
- Avoid their heels slamming down and creating a loud slapping noise.
- Being able to maintain the landing with good posture and without excess strain in the neck and face.
- Retaining control of their knee valgus (inward turn). A small amount of valgus is acceptable for some athletes, but typically indicates either poor hip control or lack of leg strength in the developmental stage of that athlete’s career.
- Staying in control of their maximal knee bend. This is individual to each athlete, but a coach should be able to notice if the force of the drop is driving an athlete into excess knee flexion.
If you are using outcome goals, increasing the box height until an athlete’s rebound jump performance starts to decrease significantly is also a nice way to determine an athlete’s reactive ability and which box they are ready to use. If the best clearance an athlete can manage is a 48” hurdle off a 24” box, and they can still clear the hurdle jumping off 30” and 36” boxes, but a 48” hurdle clearance off a 42” box is no longer possible, you know that 36” is a good high-intensity choice, while 24”-30” will work well for reduced ground-contact time work.
When in doubt of box height, be conservative. It is better to make an error in lowering a box 4” from the optimal level than to go 4” the other way! Nobody’s season gets ruined because they used boxes on the lower end of a possible range.
If you have a contact mat, it is useful practice to record athletes’ ground-contact times from various box heights as well. An athlete may be able to jump 30” from a 24-, 30- and 36-inch box, but you may find that their ground contact times increase significantly in the process. This will be important information when we get into the differences between the speed and strength orientations of depth jump performance.
The important difference of Depth Jump vs. Drop Jump
Natalia Verkhoshansky, daughter of the legendary depth jump inventor Yuri Verkhoshansky, has shed light on different ways of implementing depth jumps in training. She places the exercise into two distinct categories: the drop jump and the depth jump. Both involve dropping from a box and rebounding for maximal height upon landing, but have important differences that can help us gain greater insight into the actual purpose of the exercise itself.
The drop jump is a type of depth jump characterized by minimal knee flexion and minimal ground contact time upon landing. The recommended box height of the drop jump is very low, around 8-24 inches (20-60cm). This is a common prescription of many track and field coaches, who don’t want to lose ground contact time or landing quality.
A drop jump can also include a more flat-footed landing, which caters towards the instant reversal of direction of the movement. I had discussions in my grad school years with experienced track coaches who were adamant about the need for a flat-footed landing, where previously I had seen plenty of sources that cited landing on the balls of the feet. The difference here in landing isn’t black and white, but rather dependent on the type of depth jump being performed. For the most part, track and field athletes, particularly jump athletes, are well served by working on flat-foot landings that minimize ground contact time and replicate foot strike in their event area.
Video 3. This is a good representation of a drop jump.
They can also benefit immensely from the other type of depth jump, the classical version, which I’ll describe. It is characterized by a knee bend that is either at, or slightly less than, an athlete’s typical amount of knee bend in a standing vertical jump. The box heights are also significantly higher in many cases, around 30”-45” (70-110cm). A 45” depth jump takes a very elastic athlete with a lot of plyometric experience, so never forget that box height is based on an athlete’s individual ability.
Finally, whereas the drop jump focuses on minimal ground contact time and quality of muscle stiffness and landing mechanics, the depth jump is more oriented towards maximal rebound height. Therefore it must be paired with an outcome goal, such as a high rebound back up toward a target such as a Vertec or basketball hoop. For track and field athletes, the depth jump can be performed over a high hurdle for much specific effectiveness.
Check out this video depicting a depth jump performed by an Auburn football player for maximal height (hence the use of the contact mat). This is clearly not a drop jump, and is done for maximal explosive power rather than reactive plyometric ability, as seen by the huge knee bend. I recommend that athletes try to use slightly less knee bend than they naturally would in a vertical jump for depth jump performance, to maximize the power impulse. The the less the knee bend in the depth jump, the more it will likely transfer to running jumps and other high-velocity activities.
Video 4. This depth jump performed by a football player represents an extreme example of a strength oriented jump. This player will need to utilize jumps with less knee bend to increase his reactive ability, although this is extremely impressive from a raw power standpoint.
Specific depth jump outcomes and variations
To acquire a more powerful result from a depth jump, outcome goals should be a part of the process. My graduate school research centered on this particular phenomenon in my study, “Kinematic and Kinetic variations among three depth jump conditions in male NCAA Division III college athletes.” I recruited 14 athletes from various sports requiring some level of jumping ability, such as basketball or track and field. I compared the results of three types of 18” (45cm) depth jumps with various outcome goals.
- A control jump. Drop from the box, land, and rebound as high as possible.
- A depth jump done over a collapsible hurdle set to the athlete’s individual jumping ability.
- A depth jump, with a rebound to touching as high as one could on a Vertec measuring device.
I found a few very important points in the implementation of the depth jump exercise:
- The control depth jump was the weakest of the three variants in terms of peak vertical velocity at takeoff. It also tied for the worst (longest) ground contact time with the overhead target.
- The Vertec depth jump was a great way to get an increased peak vertical velocity in the jump. To reach the overhead target, athletes utilized a strategy of increased knee flexion to reach a higher jump height.
- The hurdle depth jump was the most powerful variant, in terms of the reduction of ground contact time (around .1 second, or 25% less contact time than the other two). Surprisingly, it also created the highest peak vertical velocity at takeoff, which I thought the overhead jump would have accomplished. To jump higher with less contact time, subjects created more power in their hips and ankles, which shows that this should be a staple variation for track and field athletes.
The bottom line with designing outcomes for depth jumping is that goals should be fairly specific to the type of sport. Basketball players can perform depth jumps with a basketball in their hands, trying to dunk the ball on a rebound. Volleyball players could perform a depth jump with a lateral drop off the side of the box into a blocking jump. The possibilities are endless and limited only by the creativity of coaches, who simply remember the frame of ground contact and the general muscle recruitment their individual sport tends to demand.
Single-leg depth jumps are another great method of performing the depth or drop jump. Although one would immediately think that single-leg depth jumps would be specific training for single-leg jumps in sport, counter-intuitively they are not. A single-leg depth jump registers a fairly long ground contact time, around a half-second, more similar in nature to a standing vertical jump than a jump off one leg. Strangely enough, when I was performing a large volume of single-leg jumps back in high school, I felt much more power in my two-leg takeoffs than anything.
Common errors in depth jump implementation
According to sport science experts, as well as personal experience, the depth jump may be the most improperly performed exercise in the sporting world today. The rise of barbell sports such as CrossFit has brought a higher standing of barbell competency to the training world, but we are still quite behind in teaching movement skills more specific and transferable to the athletic result! That said, here are common errors in the depth jump exercise.
- Box height is too high for the elastic ability of the athlete.
- Box height is too low to create an optimal, or adequate, overload, this being the case primarily when the athlete is attempting to do a depth jump rather than a drop jump.
- Depth jumps are performed in a state of inadequate physical readiness. This is far and away the biggest crime of inexperienced and unaware coaches. Depth jumps are a powerful overload exercise that requires a high level of CNS readiness. Performing them with poor quality will only lead to further overtraining and bad technical habits.
- Performing depth jumps in excessive volumes. The exact volume will depend on many factors, but athletes should never perform more than 40 in a session. My track and field athletes would never do more than 20, as we would often treat each depth jump as its own individual rep, done with full rest and recovery, and an outcome goal that often increased in difficulty.
- Lack of effort in the depth jump. The exercise is really only useful if it is approached from a maximal mentality. Drop jumps from low heights can still be effective when performed qualitatively and somewhat sub-maximally. They can still improve the efficiency of the muscle-tendon complex, even without a maximal CNS output. This is submaximal approach can be a useful tactic in developmental athletes.
- Depth jumps are often performed with no coaching regarding the quality of the landing. It should be as soft and silent as possible for depth jumps, and on a rigid foot for drop jumps.
- Most coaches never think about the horizontal distance an athlete falls during depth jumps. Often they drop straight down, and then straight back up. But this doesn’t do a great job of replicating jumping in sport, which almost always involves converting some amount of horizontal force to vertical, unless we are just talking proficiency in a standing vertical jump.
Thoughts on depth jumping for various athletic populations
I’ll end with some thoughts on utilizing depth jumps for athletes of specific athletic populations. Clearly the needs of no two are the same, so it makes sense to note some training anecdotes catering to individual populations.
Since depth jumps were more or less invented to improve the performance of high jumpers, it would make sense that they might play an important role in their development. The best version of the depth jump for high jumpers depends slightly on their takeoff style preference. Other events, such as the long jump, generally require a very short ground contact time at takeoff, around .12 seconds, whereas the high jump can see takeoff times of anywhere from .14 to over .2 seconds in high-level jumpers.
High jumpers are always looking to produce more force in less time, but they shouldn’t only look at the drop jump version of the exercise. Depth jumps are the best possible way to increase total magnitude of force output in the lower body, even if it isn’t truly specific to the exact ground contact time.
Depth jumps are more of a nitrous fuel to the high jumper, and their takeoff shouldn’t be built on a foundation of depth jumps, but rather specific unilateral work. This being said, a nice balance for most high jumpers is 60-70% speed-based drop jumps, and 30-40% depth jumps, performed to an outcome goal of a hurdle or overhead target. For some inspiration, check out this great video of an intense jump from Russian high jumper Rudolf Povaritsyn (PR 2.40m).
Video 5. Perform this depth jump, and perhaps you too can high jump 2.40m.
The same vertical force production that depth jumps offer sprinters is quite useful for horizontal jumpers. Generally speaking, these athletes may do better with a greater respective volume of drop-jump type activities. Ground contact time must be very closely monitored, particularly in seasonal periods when a high level of reactive strength is required. A good volume of low-box-height drop jumps is not as intense as their depth jump brethren, and can be a nice way to help build specific horizontal jump fitness in the SPP training periods.
Are depth jumps necessary to build a world champion sprinter? Of course not. Are they a useful tool in the development of the majority of sprint athletes? Sure. Sprinters do well with depth jumping, as the single-response depth jump can help improve the quality of more common, repetitive vertical plyometric efforts such as hurdle hops. The depth jump is one of the best special strength exercises available for sprinters in terms of improving the magnitude of their ground reaction force, as well as providing a strong neural signal to the lower body. Athletes who need improved acceleration qualities will do better with a higher volume of the depth jump variety, while those seeking improved top-end speed will cater towards variations over hurdles, as well as drop jumps.
Sports placing a higher priority on two-leg takeoffs will breed athletes who utilize longer ground contacts to produce power. With that in mind, the quickness of jumping is a critical area of importance for success in these two sports. A basketball player jumping for height may have twice the ground contact time of a track and field long jumper performing the same skill. Properly administered depth jumps can help reverse this trend by allowing these athletes to reduce their ground contact time, thereby getting off the ground quicker.
Care must be taken when administering depth jumps and their derivatives to these athletes. Many of them are already undertaking dozens—if not hundreds—of jumps during each practice session or competition. Remember that a close balance exists between the volume of competitive and special exercises. If the volume is too high, general strength work needs to fill the gap. In many cases, performing drop or depth jumps from lower boxes as more of a skill development/refinement drill can have a better effect on the readiness state of these athletes than pounding on them with intense, outcome-related depth jumps.
Throwers, Football Linemen, and Other Large Athletes
I don’t have much experience using depth jumps with larger athletes who rely on absolute strength more than relative strength. But my recommendation for this population would be simply to avoid higher box heights, and cater towards outcome goal-based efforts. Also, don’t be too harsh on their tendency towards longer ground contact times. Just because a thrower or football player might sport an excellent strength-to-bodyweight ratio, it doesn’t mean that their tendons and ligaments can handle the exponential loading that occurs in a drop from a high box. Short ground-contact times are as much a product of physics and anatomy as they are strong muscles.
Depth jumps should be used with care in the process of developing young athletes. Some youth training experts, such as Mark McLaughlin, the co-founder of Performance Training Center, are known not to use maximal depth jumping as a preparatory exercise for high school athletes, to reduce the effects of early training intensification, and to set them up better for their college sporting years and beyond, something so many coaches are afraid to do or lack the egotistical restraint to consider. Here’s a sample of Mark’s working methods for training youth athletes.
When deciding on depth jumps for young athletes, a general rule is to keep the box height very low (under 18” or 45cm), and to keep them qualitative rather than quantitative. Low box drops and jumps can be a great way to teach loading and reactive mechanics, but the focus should be on the mechanism of the landing and jumping rather than the height of the jump itself. Depth jumps are often the cherry on top of a properly implemented plyometric program, and should never be the first serving for any athlete seeking long-term development.
Like any powerful training stimulus, there is always a duality present. Depth jumps may be the most potent exercise available for those seeking vertical jump and general power improvements, but they must be performed correctly, at the right intensity, at the right time. When done correctly, they can turn average jumpers into great jumpers and great jumpers into champions. When done incorrectly, they’ll provoke injury, over-intensify training, and cause general havoc in the long-term development of an athlete. Knowing how to harness this powerful training tool is the feather in the cap of any coach.