Your heart rate is the rate at which your heart beats per minute commonly known as pulse. The heart rate can vary depending on your age, weight, training and temperature. As a thumb rule, the fitter you are, the lower your heart rate because your heart muscles are working more efficiently. This is because just like other parts of your body, the heart is made of muscles and training can improve the muscles in your heart.
Your resting heart rate is your pulse when you are sitting in a calm state and best measured in the morning. A normal target range for the resting heart rate is between 60-100 though really fit atheletes and buddhist monks have been known to have a resting heart rate even as low as 40. When you exercise, your heart beats faster to pump blood and oxygen to your muscles. Your ability to get your heart rate up (target heart rate) determines the effectiveness of your work out.
The maximum rate at which your heart should beat or target heart rate is calculated by subtracting 220 from your age. As an example, say you are 30 years old. Your maximum heart rate is (220 – 30) = 190 beats per minute.
Knowing your maximum heart rate is useful because your ability to benefit from any exercise you do depends on the rate of your heart beat while exercising. According to the American Heart Association your heart rate should be between 50% and 85% of your maximum heart rate. So for a 30 year old, your target zone is between 95 (50%) and 162 (85%). Depending on how vigirously your exercise and the duration of your exercise your body will benefit from the exercise.
Your heart rate training zones fall into four categories.
The Recovery Zone is when you almost exclusively burn fat and happens when your heart rate is between 60%-70% of your target heart rate. In this zone, the efficiency of the heart in pumping blood and feeding oxygen to your muscle improves.
The Aerobic Zone is when you are training with your cardiovascular system and happens when your heart rate is between 70%-80% of your target heart rate. In this zone, your body is able to transport oxygen to your muscle and remove carbon dioxide away from your muscle more efficiently.
The Anaerobic Zone is when you are able to train at 80%-90% of your target heart rate. In this zone, your body is able to use the glycogen stored in your muscles as the main source of energy.
VO2 Max Zone is reached when you between 90% adn 100% of your target heart rate. This is a zone you should only target only if you are very fit and for very short periods of time. In this zone, the lactic acid builds up very quickly. The benefit is that you develop fast twitch muscles which increases speed.
Any form of exercise that gets you into the aerobic and anaerobic zones for at least a part of the duration maximizes the utility of your exercise. That is the difference between walking around the house or being “active” and some form of vigirous exercise.