It is important to warm up for at least 10 minutes immediately before exercising. Slowly stretching your muscles helps increase blood flow and can prevent injury to your muscles, tendons (strong tissue connecting bones and muscles), and ligaments (a tissue holding the bones together). Try to stretch all the major muscle groups (your chest, abdomen, shoulders, arms, and legs) before starting your exercise. Begin your warm-up gradually, stretching slowly and carefully. Never bounce or jerk your body while warming up. Stretching will improve your flexibility.
The following are a few simple stretching exercises that will enable you to warm up:
Head and neck - Roll your head slowly around in a circle, bending your neck so that you face at the back of the circle, and down at the front. Repeat 5 to 10 times.
Arms and shoulders - Stand with your back straight and your feet about 1 foot apart. Raise and extend your arms and slowly rotate them backward 5 to 10 times, then forward 5 to 10 times.
Shoulders and chest - Stand with your back straight and your feet about 1 foot apart. Join your hands behind your back and slowly raise your arms until you feel the muscles in your upper chest and shoulders start to stretch. Repeat 5 to 10 times.
Trunk - Stand with your back straight and your feet about 1 1/2 feet apart. Bend to the right at the waist, sliding your right hand down your leg to just below the knee. Straighten, and then do a similar bend to the left. Repeat 5 to 10 times.
Hips and trunk - Stand with your back straight, bend forward at the waist, and bring one leg up to touch your face with your knee; then straighten. Do the same with your other leg. Repeat 5 to 10 times. Hold your arms out sideways, with your feet slightly apart. Slowly swing your arms and upper body to face right, and then swing around to face left. Repeat 5 to 10 times.
Knees and calves - Stand with your back straight and your feet together. Carefully move one leg forward, putting your weight on that leg, and bending your knee. Do the same with your other leg. Repeat 5 to 10 times.
Most people mix warm up with stretching, they are totally different and the only thing common is that they are done before the workouts.
Warm up exercises are not vigorous exercises. Any light exercise such as spot jogging, walking and cycling at slow pace can be done to warm up.
A proper warm up prevents fatigue and reduce strain and muscle pulls and soreness.
Warm up should be followed by some stretching exercises before starting the workouts.
Developing flexibility is a slow process. Stop before hitting your pain threshold.