The majority of bodybuilders have this false notion that they need to feel sore as hell for several days after their workout to deem it “successful”.
The feeling of soreness indicates an inflammatory response in your muscles to mechanical stress(exercise). The satellite cells in your muscles, which are the dormant precursor cells in charge of repairing the damaged muscle tissue, are a key part of muscle hypertrophy. It is believed that the presence of inflammation has a big role in the process of building new muscle tissue.
One study examined two groups of subjects, trained and untrained people, which were put on an eccentric-overload workout routine for eight weeks.
The scientists measured the level of inflammation and muscle soreness and took a muscle biopsy of the participants’ legs. When the study ended, it was concluded that the untrained subjects experienced initial muscle soreness symptoms, whereas the trained subjects didn’t.
It’s interesting to point out that both groups experienced similar increase in IGF-1 (Insulin-like growth factor 1) protein expression in the muscle tissue and experienced similar hypertrophy increases.
It was also found that these increases in muscle hypertrophy, strength and IGF-1 expression occurred independently of the blood levels of indicators of muscle damage like creatine kinase.
The most important take-away point of this article is that just because you don’t feel sore, doesn’t mean you didn’t train hard enough.
Feeling sore is a bad indicator of proper training. Experienced athletes tend to develop a protective mechanism which prevents them from experiencing further muscle damage, known as the “repeated bout effect. Don’t think you’ve wasted a workout, just because you don’t feel sore.
Reference : Muscle damage and muscle remodeling.