The Short Bridge is a nice little exercise that marks the start of the bridge progression. Few people around the world use this exercise (or other steps of the bridge) in their normal routine, but, if you want a really healthy, strong and flexible spine that prevents your lower back from being hurt, you should do it on a regular base. Bridge exercises train your lower back muscles, your spinal muscles (the deep ones as well), the rear hips and the back of your thighs. Their interaction (which is used to a lot of daily moves) is trained as well. You also need a strong spine to forward the power from your legs to your upper body (like used in strong punches). The muscles around the spine are no show muscles...but without them your spine (and the spinal cord with all its nerves) is as vulnerable as a raw egg. If you hurt your spin it could happen that you lose the ability to move your legs or, worse, to move your whole body (and then you have a problem to maintain the show muscles...). If you want to protect your spine and its functions (which you definitely should) you have to build strong (not big) muscles as a flesh armour at your back. And the best way to do this is by bridging. Bridging gives you strengh, flexibility and a perfect posture instead of the bad posture you get from sitting on a chair every day. It also prevents and heals back injuries. Lots of reasons why you should start with it, don't you agree?
I hope you understand the important of a strong spine now...let's start with the how-to-perform explanation:
Lie down on your back and bend your knees (feet shoulder width apart). Your feet should be flat and around 6-8 inches away from your butt and your arms should be crossed in front of your chest. Now press down through your feet and lift your hips and your back off the floor until your thighs and trunk forms at least a straight line and your bodyweight is supported only by your shoulders and feet (2 sec). Hold the position for 1 sec and reverse the motion until you almost touch the ground again (2 sec). Now start the next rep without a rest. If you can't manage to meet the target instantly, do every time as much reps as possible until you can do the requested amount.
Target: 3 sets of 50 reps
Paul recommends to do the exercise only once a week but I prefer to do it twice (see "The Plan").
Time to start working your spine and back!