This exercise is easy for anyone to do and at any fitness level.  The traditional bridge targets and strengthens the low back, glutes (butt muscles), and hamstrings.  It also strengthens your core (trunk musculature) which is important not only in sports but also for everyday normal activities.  Additionally, for all the great benefits you achieve from this exercise it doesn’t require a lot of time or equipment.  Shown in the illustrations below this example of the bridge also incorporates the inner thighs. 

• Lie face up on the floor with hands at sides, palms down, knees bent and feet flat on the floor.
• Engaging your abdominals, lift hips and back off the floor until your body forms a straight line from shoulders to your knees.
• Keep feet on floor and don’t overarch the back.
• At the top of the movement, squeeze the glutes and bring knees out to sides as far as possible; return to center, lower, and repeat.
• Do 3 sets of 12-15 repetitions.