MUSCLES ENGAGED Calves Calves (calf muscles) influence the ankles and contribute to overall ankle strength. Strengthening your calf muscles will help your balance and performing movements such as running, walking and jumping. Hamstrings The hamstrings play a crucial role in many daily activities, such as, running, jumping, walking and cycling. Strengthening your hamstring muscles help to protect your knees from injury by absorbing the stress placed on the knee. Weak hamstrings can lead to knee injury. Exercise Instructions Step 1 Start skipping and jog on the spot. Step 2 Keep jogging on the spot and start pulling your knees up as high as you can. Step 3 Keep your knees above your hips for as long as you can.