How Fit Is Your Fitness Knowledge?

Keeping fit could be as simple as separating fact from fiction.

To help, try your hand at this quiz offered on "The Early Show" Tuesday by Adam Campbell, fitness director of both Men's Health and Women's Health magazines.

Campbell is the author of "The Men's Health Big Book of Exercises: Four Weeks to a Leaner, Stronger, More Muscular YOU!"

In the quiz on the show, he debunks some common fitness myths.

Bev Ratcliff, a fitness contributor to both magazines, joined Campbell to demonstrate the proper way to do the exercises he mentions.

CRUNCHES ARE ONE OF THE BEST MOVES TO TARGET YOUR ABS. FACT OR FICTION?

Fiction. Don't do crunches; do planks. Crunches do work your abs, but they require you to round your lower back repeatedly, which can be harmful for your spine. The plank however, targets your entire core while also reducing your risk for lower back pain.

Assume pushup position, but put your forearms on the floor instead of your abs. Now tighten your core - as if you're about to be punched in the stomach - and hold for 30 seconds. Rest for 30 seconds and repeat two more times. This really works your core. This works everything, all your muscles from your shoulders down to your butt. It looks easy, but isn't really.

CARDIO BURNS MORE CALORIES THAN WEIGHT TRAINING. FACT OR FICTION?

Fiction. We've all heard this, but the NEWEST research shows that a fast paced weight workout burns as many calories as running at a six-minute-mile pace. You don't need a complicated workout, though. Start with a bodyweight squat. If you've never lifted a weight before you can start with a body weight squat. A weight training workout can be with dumb bells or just using your own body weight.

Push your hips back, then bend your knees, and lower your body. Do as many reps as you can in 20 seconds, rest 20 seconds and repeat 5 times. That'll take less than 4 minutes, but it's a simple way you can burn calories and get fit in your own living room.

LIFT WEIGHTS SLOWLY AND YOU WILL INCREASE THE BURN. FACT OR FICTION?

Fiction. Generally speaking, lower the weights slowly, but lift them fast. Lowering slowly helps you build strength faster; lifting fast activates more fast twitch muscles, which are the ones that require the most energy to contract. And that means more calories burned. Rule of thumb: Take 3 seconds to lower and one second to lift.

WEIGHT TRAINING INCREASES FLEXIBILITY. FACT OR FICTION?

Fact. A lot of people think that lifting weights makes you muscle bound, but it's really just the opposite.

A good example of why is the lunge: Every time you do a repetition, you're stretching the muscles of your hips and thighs. A version we really like at Men's Health and Women's Health is called the curtsy lunge: Instead of stepping straight forward, cross your leg in front of your body. This not only increases your flexibility, but it also improves your balance. And that's just one of more than 30 variations of lunges that I put in my new books.

ALL TIGHT MUSCLES NEED TO BE STRETCHED. FACT OR FICTION?

Fiction. Stretching is good, but muscles can feel tight due to weakness in another muscle. For example, if you think you have tight hamstrings, it's often a sign that your butt muscle or glutes are weak. This is a really common weakness and it also causes your hip bone to tilt forward, pushing your belly out! The solution? A simple bodyweight exercise called the hip raise. Tighten your core and squeeze your butt muscles-pretend you're squeezing two fists. Now push your hips up and hold for 5 seconds. Lower and repeat until you've done 10 reps.