The Heart of Fitness
The heart lies at the centre of our cardiovascular system, which also comprises the lungs and the circulatory vessels, ie veins and arteries. One of the major roles of the cariovascular system, is to oxygen to the muscles. For only when oxygen is present, can the muscles release the bulk of tries stored energy.
The more oxygen that the cardiovascular system can greater the body’s capacity for endurance events like running and swimming. The word aerobic means with oxygen which is why this type of activity is called aerobic exercise.
Your aerobic fitness is usually measured in terms of the maximum amount of oxygen you can supply to your muscles which is referred to as your VO2 Max. In order to improve the efficiency of the oxygen delivery system, it is necessary to elevate your heart rate to between 65% and 85% of maximum, for a period of 20-30minutes. This is usually achieved using machines like cycles, treadmills, rowers and steppers.
After a while you will begin to fatigue, the oxygen supply will diminish, and your body will produce a substance called lactic acid. Once this gets into your muscles, it causes the soreness which makes you stop. As your fitness level improves it will take longer before this occurs.
Eventually the heart will become stronger. The amount of blood it pumps out with each beat will increase, and the substance in blood which attracts oxygen called haemoglobin will also multiply. You will be able to work for longer at higher intensities without fatiguing. In other words you will get fitter.
In addition to an increase in aerobic capacity, you will also burn body fat, lower cholesterol levels and feel an increased level of energy. Clearly the value of cariovascular conditioning is enormous, and the benefits can be yours in exchange of just one hour of your time three times per week.
Category: goodHEALTH