A:  This is a good question because it deals with both pain tolerance and how we all differ in those areas, but also with how we recuperate and what it means to our overall growth and progress when recovery collides with simple "muscle clearing" of lactic acid.  Some light training to rid the body of soreness is always a good idea. It moves the waste products of your last workout out of the muscle and you recover much more quickly. So here's a good rule of thumb:  If you still feel sore from your last chest workout, and you're going to do chest, try doing some lactic acid clearing sets - just real light stuff. If your muscles don't feel loose and pliable and you still feel terribly sore, leave the gym, go home, jump in the jacuzzi, hit a cold shower, and hit the bed. You need to recuperate. You also probably need some recovery supplements that help you recover faster. Glutamine is a great start - 3 to 4 grams after each hard workout - and drink a LOT of water. If you are natural, recovery is so essential and there is absolutely no compromise. If you take AAS, it's a little easier, but still important. We think natural lifters should train M-F - one body part a day - period. You need a full week's recuperation.  Use your good judgment.