Fitness expert Andrea Orbeck tells you how to get the most from your workout--and how to get on the fast track to fitness without spending hours in the gym. Read on for her tips to a better body.

1. Only sticking to cardio
You've heard it before-strength training is key. It helps you build muscle, which in turn torches more calories throughout the day. Do 30-60 minutes of strength training moves, 3-4 times a week, Andrea recommends.

2. Thinking more is more
Spending too much time in the gym can derail your workout. Overdoing exercise can not only lead to injury, it can make you loathe exercise. So instead of spending every waking our pumping out cardio, stick to shorter, higher intensity workouts to blast calories. And make sure you let your body recover!

3. Not eating enough
You may believe that starving yourself is the only way to drop the pounds, but not fueling your body can backfire. It slows your metabolism and puts your body into starvation mode, which means you're not burning as many calories as you would when you were properly nourished. Plus, your workouts will suffer because you won't have as much energy to exert to a sweat session.

4. Doing the same workout repeatedly
News flash: your body is smarter than you think, so if you're spending all your time doing one workout (i.e, reading a magazine while exerting minimal effort on the elliptical) five days a week, you're not going to see optimal results. The key to changing your body is to mix up your routine and challenge your body.

5. Not eating enough protein
Protein builds muscle. Muscle burns more calories than fat. If you don't eat enough protein, you'll not only feel hungrier, leading to possible binges when hunger strikes, but you won't be as toned if you aren't giving your body what it needs to create lean muscle.

6. Giving up when you don't see immediate results
Many people get frustrated when they log in hours at the gym but don't see a drop on the scale. But they are putting too much emphasis on that major number they want to get to, not on how they feel. If you're hitting the gym, you're gaining muscle (and losing fat!), so even if you're not seeing a dramatic decrease in weight right away, a better measure of your progress is to see how your clothes are fitting you.