When most women say that they want to "tone up," what they usually mean is that they want to become leaner. Basically, they want to lose fat, and add a little muscle definition—but not so much muscle mass that they look like a bodybuilder. Here are some helpful guidelines for toning up without bulking up.
Myth #1: Lifting light weights will tone your body and lifting heavy weights will bulk you up.
The Truth: While there is some truth to the idea that lifting lighter weights for more reps does a better job of increasing the muscular endurance, lighter weights will not help you "tone" better than heavy weights. In fact, because heavier weights build the strength of your muscles--thereby helping to increase your metabolism and burn fat--lifting heavier weights with fewer reps (8 to 12 on average) and working until you're fatigued is more effective at helping you reach your toning goals than lifting lighter weights.
Myth #2: Lifting light weights won't help you get stronger.
The Truth: When it comes to lifting weights, the secret to really getting stronger isn't about how much weight you're lifting. Instead, it's all about working your muscle to fatigue where you literally cannot lift the weight for another repetition. The August 2010 study from McMaster University that proved this found that even when subjects lifted lighter weights, they added as much muscle as those lifting heavy weights. However, the time it takes to reach fatigue with light weights is much longer than the time it takes to reach fatigue with heavier weights.
Myth #3: Certain forms of exercise build long, lean muscles.
The Truth: Many forms of exercise claim to lengthen the muscles or develop "lean" muscles, not bulky ones. But here's a truth that may be shocking to some: To put it another way, no form of exercise makes muscles "longer" because your muscles do not—and will not—respond to exercise by getting longer. It's just not how they work. Muscles are a certain length because they attach to your bones. A wide variety of movements and exercises can help you strengthen your muscles without necessarily making them bigger. In fact, you can develop a lot of muscular strength without your muscles ever increasing in size (girth). That said, exercises such as yoga, Pilates, dance and barre classes can help to increase your flexibility (improving your range of motion at certain joints) and your posture, which can give you the illusion of feeling and looking longer or taller.