·It mobilizes the oxidative energy sources so that it is easier to switch to aerobic energy production. This is achieved by increases in the heart and respiratory rates.
·There is reduced viscosity in the muscles, so they can contract and relax more quickly.
·There is increased speed and force of contraction of the muscles.
·The increased temperature increases the enzyme activity within the muscle fibres while improving the extensibility of the fibres and tendons.
·Warming up alerts the nervous system, therefore preparing you physiologically and psychologically for the strain to come.
Warming up before and after resistance training is very important. To prepare the body for higher levels of effort, as well as a focused mind, a warm up prior to training is vital. Some light aerobic activity gets the blood flowing to the muscles, and some stretches loosen the joints. Better yet, perform your resistance training after your cardio respiratory workout and flexibility training, and you will save yourself some time.
The benefit of a warm up is that the muscles torn most frequently from neglect from a warm up are the antagonists (such as the hamstrings) to the strong contracting muscles (such as the Quadriceps). Cold antagonistic muscles relax slowly and incompletely when the agonists contract, therefore retarding free movement and accurate co-ordination.
At the same time, the force of the contraction of the agonists and the momentum of the moving part exert a great strain on the unyielding antagonists. Without a warm up, this may lead to the tearing of the muscle fibres or the tendons.
Cool Down
Just as one gradually increases the amount of work prior to strenuous exercise it also makes sense to gradually decrease the amount of work following sports training. Following intense activity blood has been diverted to working muscles and has a tendency to "pool" in the extremities, especially the legs. Light rhythmical activity involving the muscle groups will aid the blood to return to the heart and prevent pooling and consequent dizziness and nausea. Stretching activities during the cool-down will also prevent muscle soreness following exercise. Gradually bringing the body back to normal also helps psychological wind-down and promotes mental relaxation at the end of the exercise session, allowing time to consider the feeling of satisfaction and benefit that exercise can bring.
Why Cool Down?
After you've reached and maintained your training heart rate level in the aerobic portion of your class, it is important to recover gently. The cool down serves two purposes: 1) it reduces your pulse; and 2) it returns the blood to your heart in sufficient quantities to rid the muscles of lactic acid (a chemical result of muscular fatigue). If you stop suddenly, the blood will pool in your legs instead of returning to your heart. Dizziness, nausea and a "worn out" feeling are common symptoms of an improper cool down.
Slow down gradually after exercising vigorously. Cooling down prevents feeling faint and passing out.
When you sit or stand, your heart's major task is to raise blood from your feet. When you exercise, your heart's main function is to pump blood to your exercising muscles. If it had to do the extra work of raising blood from your feet, it would pump so little blood to your muscles that you would tire with the mildest exercise. Therefore, you heart has to depend on your leg muscles to raise blood against gravity. When your leg muscles relax, the veins near them fill up with blood. When they contract, they squeeze the veins near them and pump blood up toward your heart. Alternately contracting and relaxing leg muscles pumps extra blood through your body. When you stop suddenly after exercising vigorously, your leg muscles stop pumping and your heart has to pick up the extra work. To make your heart beat faster and stronger, your body increases production of its own natural stimulants called adrenalin and nor adrenaline. This can cause the heart to beat irregularly, depriving your brain of adequate oxygen, so you feel dizzy and can even pass out. People with heart disease can develop irregular heartbeats.
Cooling down does not prevent muscle soreness. It increases circulation and helps to clear lactic acid from your muscles at a faster rate, but muscle soreness after exercise has nothing to do with lactic acid accumulation. It is due to muscle damage caused by exercise. So, you cool down to prevent dizziness, not muscle soreness.
Duration of Cool Downs
It takes your body approximately 3 minutes to realize it does not need to pump all the additional blood to your muscles. A safe cool down period is at least 3 minutes, preferably 4-5 minutes. All cool downs should be followed by stretching of the muscles to avoid soreness and tightness.
