Friends (and workout buddies) don’t let friends suffer with tight hamstrings. Here’s a great way to partner up for a super effective hamstring stretch.

PNF stand for Proprioceptive Neuromuscular Facilitation. Yes, it’s a mouthful. Basically it means using a brief isometric muscle contraction to override the stretch reflex. Think about falling asleep in a chair; when your head starts to drop forward, your stretch reflex activates by contracting the muscles of the neck to bring the head back to its original position. When a muscle senses increased lengthening it responds with an immediate contraction, which shortens the muscle. However, by contracting a muscle with gentle resistance for a short period of time (3-5 seconds) we bypass the stretch reflex and our bodies can quickly access more available range of motion.

PNF is probably one of the most effective ways to quickly and safely increase range and prepare the body for strength, endurance, or resistance training (including heavy loading) without decreasing force production. It is one of many highly effective pre-workout, movement preparation strategies.