The soreness or ache in your muscles are due to an accumulation of lactic acid built up during the exercise. Generally, I recommend to my patients to stop training when there is any pain as it is the body’s way of telling you that you are doing too much.
If there is onset of soreness or aches in the muscles 12 – 24 hours after training, it is normal, let the soreness and ache abate before the next session.
If the soreness persists without reducing in intensity at all, it is abnormal and please see a doctor for review.