10 Biggest Fitness Mistakes That Are Making You Fat Mistake #7:

You stick to cardio and avoid weights so you don’t bulk up.

Sure, lifting weights can bulk you up (the Arnold didn’t get those biceps at Zumba class), but only if you specifically train to add mass. If you train to tone, you’ll tone. You have total control over the effect weight lifting will have on your body. And guess what? The size of the weight has little to do with muscle mass. The size of your muscles is determined by three main factors: Genetics (were you born with the structure for large musculature?), gender (men have a greater potential to put on size) and type of training (it’s not the size of the weight but how you lift it). In general, if you use light weights (three to eight pounds depending on your strength level) and do more reps (like two sets of 12-15 reps), you’ll get sleek, lean muscle. Up the weights, slow it down and maximize the squeeze to bulk up.