The glute bridge is a great exercise for runners as it effectively strengthens the glutes and the trunk. It's also a good movement as it can be performed anywhere (it's a bodyweight exercise although load can be added), and it has several variations so there's one that's ideal for you with regards to difficulty.
The above video shows 3 types of glute bridges:
Type 1 (double leg) is a good choice if you're new to strength work. The key points are to place your weight through the heels and to lift your hips up so a straight line between your knees and shoulders is formed.
Type 2 (double leg raise, single leg lowering). Raise using both legs, but then take one leg away and lower in a controlled way with just one leg. This is beneficial as you are stronger through the eccentric (lowering) phase than you are through the concentric (raising) phase, so you'll be able to cope easier with a single leg lowering than a single leg raising. This is an excellent exercise to carry out before you progress onto the third and toughest of the 3.
Type 3 (single leg) is the most difficult and should only be carried out once you're performing type 2 comfortably. Important points are to contract your glutes at the top of the movement and to control the lowering phase so your hips move slowly and steadily towards the floor.
By Marc Brown