While working out is integral to seeing results, overtraining can actually have the opposite effect, warns Gabrielle Union's trainer, Ahmad Baari. "If you are dieting plus overexercising, you will do more harm to your body by creating a toxic environment, which results in the body holding onto fat," he explains. Instead of long, overly hard exercises, Ahmad says to focus on the quality of your reps in order to stimulate muscle growth. "Anything more will be creating an overstressed system," he says. "Your body reads stress as a signal to hold onto stored fat instead of releasing it into the bloodstream to be used as fuel to replenish your muscles."