Delayed onset muscle soreness (DOMS) is a sore and painful feeling in the muscles. This usually occurs after unaccustomed intense exercise. DOMS is thought to be due to temporary muscle damage and inflammation. The most common trigger appears to be eccentric exercises.
High-intensity eccentric exercise can cause muscle damage. DOMS occurs between 24–48 hr after exercise. Creatine kinase activity is known to increase.
Doms is more common especially in untrained individuals. It occurs due to sarcomeres tearing during eccentric exercise. The symptoms last for 24 to 48 hours, during which the satellite cells within a muscle repair the damage.
Types of muscle contractions-
Muscle contraction involves the activation of muscle fibers. Muscles produce force either by changing the length or by increasing the tension within the fibers. Based on this, there are two types of contraction;
- Isometric – muscle tension increases however the muscle length stays the same.
- Isotonic – fiber length changes however the tension stays the same.
Isotonic contraction has two subtypes; concentric and eccentric. Concentric contraction is when the muscle length shortens, and when the muscle length increases, it is referred to as eccentric muscle contraction.
Why does DOMS occur?
A greater disruption to the structural elements of the muscle and connective tissue occurs with eccentric exercise than concentric exercise.
As only fewer motor units are recruited and the force generated is distributed over a smaller cross sectional area of the muscle, there is increased tension per unit area. Hence this causes greater injury to the tissue.
DOMS generally resolved on own after a few days to a week. However, during this phase, muscle performance can be reduced. Range of motion might also get affected. A session of good warmup and cool down exercises pre and post your exercise regimen, helps reduce incidence of DOMS. It is also important to progress gradually and indulge in stretching and flexibility programs. A high load and high progression rate done abruptly, can injure the muscle, causing soreness.
Several interventions are recommended for reducing DOMS, these include-
- cold-water immersion
- Heat therapy
- manual therapy
- compression garments
- nutritional supplements.
Massage shows significant effects in reducing the intensity of the stiffness and pain felt associated with DOMS. When administered within 2 hours of activity, the mechanical pressure is believed to reduce the inflammatory process within the muscle structure. However it has no effect on muscle performance or strength post exercise.