Using Box Jumps to Improve Explosiveness
By Jose Vazquez, PT, RSCC – Texas Rangers
One of the essential goals of all strength and conditioning coaches is to improve explosive athletic power. By definition, power is the rate of doing work, and strength is the ability to exert force. While both have similar qualities, power involves a time component that makes it more sport-specific. Two of the most frequently used ways to improve power are: 1) move a large mass slowly, e.g., heavy squats, or 2) move a lighter mass faster, e.g., body weight jumps. The purpose of this post is to explain how to use box jumps to improve explosive power.
The box jump is a basic, plyometric, jumping exercise in which an athlete projects himself/herself from the ground quickly and lands with two feet onto an elevated box. When performed correctly, the box jump is an explosive exercise in which the athlete moves his body weight as fast as possible to improve lower body power. Because the impact forces on the body when an athlete jumps down from the top of the box are significantly greater than when he/she walks down from the top of the box, athletes are instructed to “jump up” and “walk or step down”. Because the center of mass of the body usually falls only 1-3 when an athlete jumps up onto a box, the limited strain of landing on the box and then stepping down to the ground makes box jumps a low-impact exercise and allows the athlete to perform more reps than in most other forms of jump training.
In addition to improving explosiveness, box jumps improve the reaction of fast-twitch muscle fibers throughout the body. They require the leg and core muscles to contract quickly so athletes can generate maximum force with each jump, and they improve the ability of athletes to absorb and reduce force quickly, make sudden stops and reduce the risk of injury.
The basic jump starts with the athlete standing in front of a 12-inch box in a half-squat position with both hands in front of the chest. From this position, the athlete swings his/her arms down, back and then upward and simultaneously extends the hips, legs, ankles and feet to jump up and land with both feet on the box.
Safety concerns. When performed correctly with proper technique and footwear, box jumps are relatively safe. To ensure safety, however, please observe the following guidelines:
- Wear the proper shoes. Wear basketball or other athletic shoes with proper arch support. Avoid jogging shoes.
- Place the box on non-slip floor and make sure that they top of the box has a large, non-slip, landing surface.
- Demand proper technique. Use good form on every jump. Land quietly on a full foot with knees bent, head up, shoulders over knees and knees over feet.
- Start small and progress gradually. Start with a 12-inch box or lower to ensure that you can jump and land with proper form on each rep. Progress only after you can perform the prescribed number of sets and reps at a given height with perfect form.
How to do it?
- Select a box height is appropriate for each athlete’s ability.
- Stand facing the box about 6-12 inches in front of the box.
- Set your core, and keeping your weight on your heels, quickly move into a quarter squat.
- As you squat, swing your arms down and back to put more force into the ground.
- At the bottom of the squat, without pausing, reverse directions, throw your arms and hands up and jump as high as possible to land on the box.
- Land on flat feet and make sure that your hamstrings are absorbing the landing by landing with your head up, shoulders over knees and knees over toes.
- When landing, think of absorbing the force instead of “sticking” the landing. You have four goals with box jumps: 1) produce force quickly; 2) absorb force quietly; 3) jump and land with perfect mechanics; and 4) train safely.
How do you know if the box height is appropriate?
- If the athlete can land quietly, the box height is appropriate. If he/she can not land quietly, the box is too high.
- If the athlete can land in the same position that he/she took off in, the box height is appropriate. If the knee bend upon landing is significantly deeper than the takeoff knee bend, the box is too high.
- Most authorities recommend that the landing position should never be deeper than a half-squat position.
How much and how often?
- Start with 2 sets of 5 jumps, i.e., 15 foot contacts.
- Gradually progress to 3 to 5 sets of 5 jumps up to 25 total jumps, i.e., 25 foot contacts.
- Rest 5-10 seconds between reps.
- Rest 2-5 minutes between sets.
- Rest 48-72 hours between two jump workouts for full nervous system recovery. Limit jump training to 2-3 sessions per week.
- Technique is extremely important. Always jump and land with perfect technique. Stop when technique breaks down regardless of where you are in the exercise prescription for a given workout. You will jump only as high and safely as your technique allows. When your technique breaks down, improvement ceases and the risk of injury increases.
- Be explosive. Each jump should require an all-out effort. Slow jumps do not improve explosiveness.
- Less is better. Keep the volume low. Start with 2-4 sets of 3-5 reps. More jumps increase fatigue which can causes form to break down form and jumps to become slower. When this happens, you stop being explosive.
- Complete rest between each jump. Rest at least 30-120 seconds between each jump. Rest more as the jumps become more difficult. Fatigue is not your friend when trying to be explosive.
- Box jumps improve rate of force development, not max force. Research indicates that you won’t gain muscle doing box jumps, but you will improve the ability of the nervous system to fire at a more efficient and faster rate.
- Don’t use box jumps as a conditioning exercise. Conditioning requires a high- volume of work. Increases in volume when jumping often results in a breakdown in landing mechanics which can lead to an increase risk of injury without an increase in explosiveness.
- Jump early. Perform box jumps early in your workout when you are fresh and can exert max power with perfect form. Jump before strength training.
- One box jump exercise per week. Pick one exercise, hit it hard, then do other things in your training.
- Jump only two times per week. Limit box jumps to no more than two times per week and always after a dynamic warm-up.
- Progress slowly, more is not better and can increase the risk of injury.
o Week 1 – 2-5 x 3-5 (2-5 sets of 3-5 tuck jumps
o Week 2 – 2 x 5 (2 sets of 5 reps of box jumps)
o Week 3 – 3 x 4 (3 sets of 4 reps of box jumps)
o Week 4 – 4 x 4 (4 sets of 4 reps of box jumps)
o Week 5 – Increase box height and perform 3 x 5 (3 sets of 5 reps)
o Week 6 – 4 x 4 (4 sets of 4 reps of box jumps)
o Week 7 – 4 x 3 (4 sets of 3 reps of box jumps)
o Week 8 – Increase box height and perform 3 x 3 (3 sets of 3 reps)
- After 8 weeks, athletes with a good base and proper technique can progress to a double leg take-off with single-leg landings, single-leg take-off (hop) and double-leg landings, single-leg take-off and single-leg landings, single-leg take-off and opposite leg landing, seated box jumps and eventually depth jumps.
Regression: Athletes who are not physically or mentally prepared for box jumps can start with step-ups to increase leg strength, squat jumps for leg power, tuck jumps to help get the knees up and gradually progress to jumping onto a lower box.
Final remarks. Full hip extension on every jump and sound landing mechanics are more important than height. Failure to achieve full hip extension will limit the carryover to explosive lifts and on-field performance. Leave your ego at the door because there are no box-jump world championships. The box jump is a classic exercise that can be very beneficial for athletes who run, jump and throw. It is great for improving the ability to produce and reduce force quickly and safely, and it is relatively easy on the joints.
Jose Vazquez, PT, RSCC is Head Strength Coach, Texas Rangers.