Since Arnold Schwarzenegger flaunted his bulging biceps and quads in the 1977 docudrama "Pumping Iron," the rule of thigh (if not thumb) has been that to get strong you need to lift weights that are uber-heavy – or collapse trying.

Well, we have a new mantra: Pump less and flex more.

Start light – five pounds for starters

Sometimes it's hard to know how much weight is enough when you're trying to build a little muscle. The solution is this – don't start with anything higher than five pounds. Starting with lighter weights will help protect you from injury. Ultimately, you want a weight you can lift at least eight times, but no more than 12. Adjust the weight as you get stronger.

Train to threshold

Do two sets of eight to 12 repetitions, resting for about 45 seconds between sets. The muscles worked should feel pretty tired at the end of the set, as if they can't lift the weight one more time. This is called training to threshold, and it makes your body feel younger!

Prime your posture

Form, too, is important when you strength train. Your head should be in line with your spine, and you should have a natural arch in your lower back. Don't lock your knees. Keep your wrists straight and firm. Pull your shoulder blades slightly toward each other and down. Lift your chest up and out. You should be able to steadily lift the weight while keeping your form. And remember to breathe! This helps keep your blood pressure in check.

Shoot for 30 percent for the best results

Working out at 30 percent of your maximum strength until you are too fatigued to do one more rep is the smart, safe way to do strength training (muscle fatigue can occur in as little as two minutes), so use weights that are just a third of the heaviest weight you can safely manage. For example, if you can do one biceps curl with a 10-pound weight that you curl up to your shoulder, a three-pound weight is smart for reps.

The 30 percent approach builds serious muscle strength and keeps the whole body humming at a higher burn rate for longer than if you pumped fewer but heavier reps. It also helps fight off extra pounds, keep diabetes at bay, and avoid injury to tendons and ligaments, so if you want to get rid of belly fat – as well as chase away anxiety – take the light and long road to muscle tone and power.