SOMETIMES, MORE MEANS LESS

Upping your mileage could make you a more efficient runner. When researchers2 compared the biomechanics of low-mileage (those running less than 10 miles a week) and high-mileage runners (over 27 miles a week), they observed in the latter greater springiness in the tendons, less muscular activity in the thigh muscles and higher knee-joint stiffness on landing. These adaptations allow for more efficient propulsion, which is likely to reduce the energy cost of running. But don’t add to your distance too much or too quickly: a 10 per cent increase per week towards your goal is plenty.