What is DOMS primarily caused by?

DOMS, or Delayed Onset Muscle Soreness, is primarily caused by eccentric muscle contractions. During eccentric contractions, muscles lengthen under tension, such as when you lower weights or run downhill. This action places a greater strain on muscle fibers compared to concentric contractions, which involve shortening the muscles, and can lead to microscopic damage in the muscle tissue.

The resulting inflammation and repair process contribute to the sensation of soreness that typically peaks 24 to 72 hours after the exercise has been performed. Understanding the role of eccentric contractions in causing DOMS helps in creating effective training regimens and recovery strategies, as well as in educating clients about what to expect following intense workouts.