How Resistance Training Cuts Injury Rates

Sports related muscle strain injuries significantly increase the risk of recurrent injury. Resistance training, according to a new study, can bring that risk of recurrent injury down.

“Muscle strain injury leads to a high risk of recurrent injury in sports and can cause long-term symptoms such as weakness and pain. Scar tissue formation after strain injuries has been described, yet what ultrastructural changes might occur in the chronic phase of this injury have not. It is also unknown if persistent symptoms and morphological abnormalities of the tissue can be mitigated by strength training,” the researchers of “Chronic Sequelae After Muscle Strain Injuries: Influence of Heavy Resistance Training on Functional and Structural Characteristics in a Randomized Controlled Trial,” wrote.

In the study, which was published on July 15, 2021, in The American Journal of Sports Medicine, the researchers measured heavy resistance training’s effect on the symptoms and structural abnormalities common after strain injuries.

The researchers enrolled 30 participants with long-term weakness or pain after a strain injury of the thigh or calf muscles in the randomized controlled trial. They were randomized to either eccentric heavy resistance training of the injured region or control exercises of the back and abdominal muscles.

For each participant, the researchers measured isokinetic or isometric muscle strength as well as muscle cross-sectional area and pain and function. By analyzing biopsy specimens from the injured area, they were also able to determine scar tissue ultrastructure.

Overall, heavy resistance training over 3 months not only improved pain and function, it also normalized muscle strength deficits and increased muscle cross-sectional area in the previously injured area.

“No systematic effect of training was found upon pathologic infiltration of fat and blood vessels into the previously injured area. Control exercises had no effect on strength, cross-sectional area, or scar tissue but a positive effect on patient-related outcomes measures, such as pain and functional scores,” the researchers wrote.

“Short-term strength training can improve sequelae symptoms and optimize muscle function even many years after a strain injury, but it does not seem to influence the overall structural abnormalities of the area with scar tissue.”