If you're a regular runner or cyclist, or indeed someone who does any sport involving running, hamstring stretches should be part of your weekly routine.
If you're an active person who ignores this kind of mobility work you raise your risk of injury, and judging by the pain on the faces of footballers on TV who twang their hammies during a match, you really don't want a hamstring injury.
To help you avoid that unpleasant fate, or just to stretch out your legs after a long day sitting at a desk, try these five hamstring stretches from Josh Cooper, head coach at fitness studio UN1T.
Sit on the floor with your legs forming a V-shape in front of you. Reach and lean towards one side at a time to feel a stretch in the hamstring in that side. You can turn this into a great mobility drill by reaching to one side and then moving your hands from foot to foot by walking your fingers along the floor in an arc.
Dynamic hamstring reach
Stand tall with one foot slightly further forwards than the other. Keep your front leg straight while flexing your ankle to point your toes towards to the ceiling. Hinge at your hips and reach down with both hands, sweeping them forwards along the floor, then return to standing. © ShutterStock
Lift one leg up onto a bench (or bed, or chair) with your foot turned out and a slight bend in your knee. Bend forwards from the hips, keeping your back straight, then slowly straighten your knee. You will feel this stretch towards the outside of the back of your thigh. Continue to bend and straighten the knee.
Place your toes on a block or weight plate with your heels on the floor. Keep your legs straight and hinge at the hips until you feel a stretch through your hamstring, and hold.
Banded hamstring stretch
Lie on your back with one leg extended and raised slightly. Place a resistance band around your foot and pull the band tight, then raise your leg, keeping it straight, until you feel the stretch, then stop and hold. Once you feel the stretch start to subside you can carefully challenge your range by bringing your foot closer to you.
Gallery: Exercising for the first time? Here's everything you need to know (The Active Times)