Walking Downhill Increases Risk of Falls in Older Adults

The Conversation reports that a new study shows that eccentric exercises like walking downhill may temporarily increase the risk of falling in older adults. Eccentric contractions can incur short-term muscle damage and sensations of muscle soreness. The study, published in Frontiers in Physiology , compared the effects of exercises involving mainly concentric contractions like walking on a level surface, with those of regimens involving mainly eccentric contractions such as downhill walking. The researchers enlisted 19 healthy older men and women who were unused to eccentric exercise, with 10 assigned to a level walking group and nine to a downhill walking group. Level walking caused a short-term elevation in the risk of falling immediately after exercise, and half an hour of level walking caused a loss of balance, reduced physical function, and muscle weakness. The higher risk of a fall immediately after concentric muscle contractions is likely due to the accumulation of metabolic byproducts that reduce the muscle fibers' ability to produce force — although the negative effects of fatigue from this type of exercise did not last long. However, there was a delayed and prolonged increase in the risk of a fall following downhill walking. The implication is that the muscle damage that occurs after unaccustomed eccentric exercise leads to muscle weakness, balance problems, and impaired physical function, which can linger for several days.