I used to think it was lactic acid buildup, but now it seems to be micro tears in the muscles. It should only happen if you just started working out from a long period of inactivity. It happens to me when I haven't worked on the muscle group for about a month. It will slowly go away in about a few days to a week and should not happen if you are consistent with your workout. The good thing is that you know which muscle group that exercise it works on. For example, if I haven't worked my chest in a long time, or if I tried a new exercise (butterfly curls), my upper chest, close to my shoulders, will be extremely sore the next day.
I used to think it was lactic acid buildup, but now it seems to be micro tears in the muscles. It should only happen if you just started working out from a long period of inactivity. It happens to me when I haven't worked on the muscle group for about a month. It will slowly go away in about a few days to a week and should not happen if you are consistent with your workout. The good thing is that you know which muscle group that exercise it works on. For example, if I haven't worked my chest in a long time, or if I tried a new exercise (butterfly curls), my upper chest, close to my shoulders, will be extremely sore the next day.
I kept some kind of a workout schedule during lockdown, but really upped the intensity lately.