Each sport places different stresses on the body and as a result, your perceived exertion for the same heart rate will differ. This means that your perceived exertion during Running will be lower than while Cycling and far lower than that for Swimming.

While running, you may find it difficult to stay in your MAF zone and you may need to walk on the uphills. This is quite normal especially in the initial few weeks of MAF based training. s running recruits more muscle groups, and because you are “overcoming gravity” with each stride, more work is being done. Also, running at slow speeds doesn’t generate the cooling effect that cycling at speed does. physical exertion and thermal stress both will lead to higher perceived exertion for the same heart rate.

While swimming, the body is horizontal so the heart doesn’t have to pump blood against gravity and the body temperature is artificially regulated by the water temperature. For the same heart rate, you will therefore be able to put in far more effort than you would for running on a warm day on a hilly course.