Warming Up for Bowling
Before performing any exercise, it is important to warm up your muscles. Bowling is no different to any other sport in this respect. While bowling may seem to be a relatively low level exercise, due to the repetitive nature of the sport, and the necessity to carry and deliver a weighted ball, it is possible for the muscles and joints to be strained.
During bowling, repeated strain is put on various areas of the body - the arms, wrists and knees in particular. Also, many muscle groups are involved in the bowling action, including the forearms, shoulder, back, torso, hips and legs. The exercises performed should include the body parts that are being used, and should take you at least through the range of motion that will be involved in the exercise. The exercises should start you off with slow controlled movements, progress to more ballistic movements, and culminate with the full bowling action.
When to warm up
The warm up should be done before each bowling session - both for competition and practice. If you have extended rest periods where you are not performing, you may have to go through some of these procedures to keep your muscles and joints ready to safely and consistently perform.
Preparing for Exercise
Initially you should begin the warm-up by doing some light activity to increase blood flow to the muscles. A short run around the block, or running on the spot, or anything similar that increases your heart rate would be suitable. The next phase of the warm up is to stretch the muscles and joints. This will be achieved initially by passive stretches followed by active stretches. See this list of stretches that you can do before bowling.