1. Step forward with your left leg and lower into a lunge over 3-5 secs, activating the hip flexors of your right leg.
At the end of your range, push your right foot into the ground and hold for a few secs (maintain the contraction in your hip flexors), or do six mini lunges before returning to standing. “Be sure your pelvis is facing forward, as it would be in the correct running position,” says Blazevich. Repeat on the other side. Do 3-5 reps per leg.