Even when you’re young and healthy, not using your legs for as little as two weeks can sap a third of your muscle strength. New research from the University of Copenhagen reveals that immobility lasting for just two weeks would reduce the leg muscle strength of a young man to that of someone 40 to 50 years older. The Danish researchers looked into the question of how inactivity affects leg muscle strength by immobilizing young and older male volunteers with a leg pad for two weeks. They report that while the young men lost up to a third of their muscle strength, the older ones lost about one-fourth. That loss is more significant than it may seem since the older men presumably already had reduced muscle strength due to age and would end up with much less physical capability than the younger group, the researchers reported. They found that biking three or four times a week for six weeks after the period of immobility didn’t completely restore muscle strength even in the younger group – the biking brought back muscle mass but to get to their original levels ofstrength, the men had to include weight training in their workouts.
My take: This study presents a rather dramatic “use it or lose it” scenario. With luck, few of us will be completely immobilized for two weeks (or more), but accidents do happen, as do illnesses that can lay you low and keep you there from time to time. It’s worth heeding this study’s message – that to restore your fitness you have to do more than just return to your usual workout, you’ll also have to include strength training (something I regard as an essential part of any exercise program along with aerobic exercise for cardiovascular fitness and stretching for flexibility).