The next time you're at the gym and your muscles start shaking or twitching during those reps, or you start feeling more tired halfway through your second set, be sure to take a breather or you might end up doing more harm then good.

While some folks might consider "muscle soreness" to be a sign of a great work out, Josh Feldman, a certified personal trainer and fitness manager at NY's Crunch Fitness, says pushing yourself to the max won't really do you any good in the long run. He explains:
“It’s way more important to be able to exercise every day or every other day than to just kill it one day and not be able to move for four or five days after that.”
So while working your muscles until they’re achy means you technically did tax your muscles to help them get stronger, it might end up sabotaging your goal of sticking with that new fitness routine.