Speed-based activities such as sprinting and jumping rely on the force exerted against the ground to accelerate movement. That pushing power comes from strong core and leg muscles. In an isometric exercise, the muscle is powerfully activated but not engaged in any movement. Isometric exercises are effective for those who need to rehabilitate muscle groups or build strength for running and jumping without equipment or much space.
A strong core helps you control your midsection as you run and jump. The plank pose, adopted from yoga, is an example of an isometric exercise for your core. Lay prone on the floor with your feet together and hands flat on the floor by your shoulders. Keep your legs and back straight as you straighten your arms to lift into a pushup position. Hold the position for 60 seconds.
The wall sit isometrically contracts the quadriceps and hamstrings, major muscle groups used in running and jumping. Stand with your back resting against a wall and slide down the wall until your thighs are parallel to the floor and your knees are bent at a 90-degree angle. Cross your arms over your chest or hold them extended in front of you while you hold the position. Hold for 10 to 30 seconds.
Isometric lunges build strength in the quadriceps, hamstrings and hips. Stand with hands on your hips and your feet shoulder-width apart. Step forward with your right leg into a deep lunge, keeping your back foot in place. Lower your body until your right thigh is parallel to the floor and your knee forms a 90-degree angle with the floor. Hold this pose for 10 to 30 seconds. Push off your right foot to return to the starting position. Repeat with the left leg.
Leg raises done isometrically strengthen the hip flexors, which are important for running and squatting, as well as the abdominals. Lie on your back on the floor with your hands flat beside your hips. Press your lower back into the floor as you raise your straightened legs. Hold your feet 6 inches off the floor for 30 to 60 seconds.