Muscles worked
Box jumps train explosiveness: producing a lot of force quickly. Your quads, glutes and calves do most of the work in the take-off, the arm swing adds speed, and your thighs and glutes absorb the landing. Because you land on top of the box, close to the peak of the jump, the landing is usually softer than when you come back down to the floor. They build little muscle, but teach your legs to work fast and pair well with heavy leg exercises.
Common mistakes
- The box is too high. You land in a deep squat, and the jump turns into a test of pulling your knees up. Pick a height where you land about as deep as you took off. A soft foam box makes a new height less daunting.
- You rush the reps. Tired and hurrying, it is easy to clip the edge of the box with your shins. Step down, stand still and start every jump from a standstill.
- The box is unstable. A box that slides or tips is worse than a low one. Use a sturdy plyo box on a non-slip floor, never a chair or a stack of plates.
Variations and alternatives
- The jump squat uses the same explosive drive without a box, landing on the floor.
- Skater hops go sideways from one leg to the other and train balance and explosiveness to the side.
- The step-up uses the box at a calm pace, for when you want to build strength or would rather not jump.
Sets and reps
Box jumps are done in low reps with full recovery, for example 3 to 5 sets of 3 to 5 jumps with one to two minutes' rest. Jump early in the session, once you have done your warm-up but before heavy squats or deadlifts. Every jump should be as high and soft as the first. The guide to sets and reps helps you plan the rest of the session.
Only raise the box once every landing at the current height is quiet and controlled, or add a set first. That is progressive overload for jumping, where quality matters more than quantity. If your knees, ankles or Achilles tendons hurt, stop jumping and have them checked by a doctor or physiotherapist.