“This pain usually peaks 24-72 hours after exercise. The type of exercise that causes the most muscle soreness is “eccentric” exercise, which is where force is generated by the muscle as it lengthens — think about walking downhill or the lowering phase of a bicep curl. Athletic man suffering from shoulder pain Soreness in the days after exercise is normal, and actually results in stronger muscles. Shutterstock There’s good news about this pain though. When the muscle cell recovers from this “microtrauma”, it gets stronger and can produce that force again without the same damage occurring. So although this strengthening process is initially painful, it’s essential for our body to adapt to our new training regime.” A great read from theconversation.com https://theconversation.com/feeling-sore-after-exercise-heres-what-science-suggests-helps-and-what-doesnt-150277