According to new research, it takes just two weeks of physical inactivity for physically fit individuals to lose a significant amount of their muscle strength. A Danish study, published recently in the Journal of Rehabilitation Medicine, discovered that the more muscle a person has, the more he/she will lose if sidelined by injury, illness, or vacation.
In two weeks, young people can lose about 30 percent of their muscle strength, leaving them as strong as someone decades older. The study found that they lost an average of 17 ounces of muscle in that short time frame. For active older individuals, they will lose about 25 percent of their strength after becoming sedentary. The study found that they lost an average of 9 ounces of muscle.