You have your runners on, your FitBit is charged, but now what?

When you exercise, your heart and breathing rates increase, delivering greater quantities of oxygen from the lungs to the blood, then to exercising muscles.

Determining an optimal heart rate for exercise depends on your exercise goal, age and current fitness level.

Heart rate and exercise intensity share a direct, linear relationship: the more intense the exercise, the higher the heart rate.

When you exercise at the highest possible intensity, your heart will reach maximal heart rate (HRmax), the fastest rate it is capable of beating.

But exercising at a maximal heart rate (HRmax) for every exercise session will not produce efficient fitness results. These high intensities can rarely be sustained, negating the potential benefit of the exercise.

Exercise makes your heart more efficient

Typical resting heart rate can vary quite substantially between people and even within an individual. Around 60-80 beats per minute (BPM) for adults is common.

Improving your aerobic fitness reduces your resting heart rate, as the heart becomes more efficient with each beat. An athlete’s resting heart rate, for instance, is typically around 40 BPM.

In fact, evidence suggests that long-term exercise training increases the size of the heart, specifically the left ventricle, a phenomenon known as “Athlete’s Heart”. A bigger heart means more blood can be pumped with each beat, and fewer beats per minute are required to maintain blood flow around the body. This is a beneficial physiological adaptation allowing athletes to exercise at higher intensities for longer.

Exercise intensity: what happens when we go ‘all out’

Muscle cells require two key ingredients to function: fuel (glucose) and oxygen.

Muscles rely heavily on blood vessels to deliver the necessary nutrients and oxygen around the body, and also to remove by-products such as carbon dioxide.

The more muscles used in exercise, the more blood is distributed towards the active tissues.

Source
ABC News

See also:

What’s the minimum amount of exercise you need to stay healthy?