After age 30, many of us start to lose 3-8% of muscle mass per decade. Age-related muscle loss and strength is called sarcopenia and is a natural part of the aging process. However, muscle loss (also known as muscle atrophy) can happen faster due to poor nutrition, after an injury, illness, or any prolonged period of inactivity. Muscle atrophy occurs when muscle cells shrink due to fewer and smaller muscle fibers and is mostly driven by inactivity. The results of less muscle mass are greater weakness and less mobility, both of which may increase your risk of falls and fractures.
Individuals ages 65+ years are especially vulnerable to muscle atrophy, since healing takes longer as we age. Unless older individuals have worked on retaining muscle mass and strength, recovering from dramatic muscle loss can take longer than someone who is younger.
Muscle atrophy doesn’t happen to everyone after a physical setback. How downtime affects you depends on your prior health, activity level, and amount of muscle mass going into the period of inactivity. For example, women and men who are regularly active have a much easier time preventing muscle atrophy even if they are off their feet for a while.
Some frustrating news.
It actually doesn’t take long for the body to lose muscle that you worked hard to build. Your bicep won't go "poof" since the muscle fibers are still there, but in about 2-3 weeks of no training, you will notice a significant reduction in strength and power. A recent study in the Journal of Rehabilitation Medicine found that older men who did eight weeks of strength training lost