Strained tendons are mostly referred to as muscle strains, and recovery time cannot be determined specifically, but is mostly related to the extent of the injury and individual differences. Muscle strain refers to excessive contraction or stretching of the muscle beyond its capacity, resulting in muscle tears or ruptures. After rest, infrared rays, elevation of the affected limb and other conservative treatments for mild muscle strains, most of the symptoms can return to normal after 4 to 6 weeks. Severe muscle strains may result in muscle ruptures or hematomas that require surgical intervention and take about 3 months or more to return to normal. Children are growing and have a fast metabolism and have a slightly faster recovery time than normal adults, while older adults have a slightly slower recovery time than normal adults. Warm-up and stretching exercises can be done before activity, and stretching exercises can be done after activity to prevent excessive muscle tension and avoid intense movements and over fatigue. When muscle strain occurs, you should stop the activity immediately, and if the pain is not reduced for a long time, you should consult a doctor in time, standardize the treatment, and strive for a speedy recovery.