To perform box jumps, you will need a stable surface—preferably a plyometric box between 12-36 inches, depending on your abilities. Assume an athletic position, with your feet about shoulder-width apart, at a comfortable distance form the box. Start the box jump by quickly getting into a quarter squat while hinging at the hips to engage the hamstrings and glutes. Then, forcefully extend your hips, swing your arms, and push your feet though the floor to propel yourself onto the box.
When landing, think of absorbing the force instead of “sticking” the landing. Mimic your landing on a cat’s example: gracefully and quietly. This will not only help you improve the deceleration phase of the exercise but also reduce the risk of injury. You should land in a squat position with your knees slightly above 90° with your chest up. Hold for 2-3 seconds, stand tall, and then step back down.
Note: Some coaches allow a jump-down between reps. I do not recommend this due to the immense pressure it can put on the knees and the tibia.
Benefits for size and conditioning
The biggest benefit of the box jump is that it improves the reaction of fast-twitch muscle fibers throughout the body. This exercise requires your leg and core muscles to contract very quickly so you can generate maximum force with each leap. Secondly, the landing phase (deceleration phase) is the most important part of a plyometric activity—it helps decrease the risk of injury and increase your ability to make sudden stops.
So how can this help you build size and conditioning? The higher and more explosive you jump, the more muscle tissue that is activated. Box jumps are great to round out your quadriceps training by tapping into some fast-twitch muscle fibers that are not usually hit during leg presses and leg extensions. The deceleration phase also requires a tremendous amount of quadriceps strength in order to land properly. Box jumps are also very demanding on the metabolic system making them a great exercise to incorporate in your fat loss training.
Since the box jump taxes the nervous system at a high capacity and requires a good amount of technique, allow yourself 1-2 minutes between sets of jumps for optimal performance. Strive for 2-3 sets of 5-8 reps for best results.
The box jump is best done after your warmup and at the beginning of your leg routine. You want to be fresh before you perform box jumps to optimally perform this movement. Place it at the beginning of your routine to fire your nervous system up and set the tone for the rest of your weightlifting workout. I have also paired box jumps with strength exercises such as leg presses and front squats as a superset to really push the quads into new muscle growth. You will be sure to walk funny the next day but your jacked quads will be well worth it.
Some workouts, particularly in the CrossFit arena, call for high numbers of box jumps in a single go. This is definitely a more advanced approach and care should be taken to ensure your safety if you do a high-volume box jump workout or if you are tasked with performing them while fatigued. In either instance, the safer bet would be to scale down the height of the box, reduce the number of reps, or, if possible, break it up into smaller components (i.e. instead of 20 straight, do four sets of five).