Sweat is running, your heart is pounding, you’re running out of air, you’re getting side stitches, and your muscles are cramping.
“Keep going.” “There’s got to be more to it than that.” “Only when I really power-up will I be effective.“
These are often the thoughts when you start fitness after a long break from training or even when you are very fresh.
The motivations are different. Simply to get fitter, to lose weight, to do something for your health or even to compete. But no matter what personal goal you have set for yourself, it is important that you train in the optimal range despite your desire to work out and reach your goal quickly. And heart rate plays a not insignificant role in this. Some people may think that pushing the heart rate up until it’s almost impossible is ideal – but far from it, depending on the fitness level, training level and objective, different heart rates are effective. If the pulse rises too high, for example, fewer calories are burned, but more on that later….
First, let’s get back to basics.
What is the job of our heart? – Exactly, to pump blood through the circulatory system so that our organs, first and foremost the brain, are supplied with sufficient oxygen, harmful substances are removed from the cells, nutrients, salts, etc. arrive where they are needed, and the mixture of fluids in the intracellular space and extracellular space maintain the ideal balance.
The heart rate indicates how often the heartbeats per minute. This can vary depending on height and weight, fitness and health status, and heart size. As an adult, the normal range is when the heart beats between 60 and 80 times per minute. At rest, of course, the body does not need as much oxygen as during physical activity. The pumping rate of 60 – 80 times is therefore sufficient to transport enough blood into the circulation that has been enriched with fresh oxygen in the lungs.
During physical activity, our muscle cells need more oxygen. Comparable to an engine, our muscles also only function when they receive sufficient fuel. This fuel is fats and carbohydrates to convert them together with oxygen into energy. For the muscles, this is ATP (adenosine triphosphate). Enzymes in our cells break down ATP into adenosine diphosphate (ADP) and a free phosphate, releasing energy. Three-quarters of this energy is used to contract the muscle. The rest goes off as heat or sweating. Now ADP has to be turned back into ATP to become energy again.
For this to happen, our body has invented two mechanisms: Aerobic and anaerobic energy production. And here again, our oxygen comes into play, transported into the cells by our heart with a good heart rate. In aerobic energy production, the body needs oxygen and water. Anaerobic energy production takes place without oxygen, but is much less effective.
Aerobic energy metabolism takes place at low exercise loads with a lower heart rate. This includes, for example, swimming or a slow endurance run.