Exercise for good health

For the hunter-gatherer society, daily physical activity was a prerequisite for survival.w1 Activities such as hunting, tool making, butchering and other food preparation, preparing clothing, carrying firewood and water, and moving to new campsites all needed physical labour.

Nowadays, as most modern societies have predominantly sedentary jobs, people spend about 38% of the caloric expenditure per unit body mass compared with late paleolithic stone agers. We tend to be physically active for recreational purposes and to get fit or maintain their fitness.1 Regular physical activity leads to numerous health improving effects. But just how much physical activity is necessary to achieve the benefits, and can exercising too much do harm?