When it comes to keeping weight off and boosting your metabolism many people believe that pure cardio exercise is the way to go.

But new research suggests you may need to add a bit of variety to your routine to maximize benefits.

Fitness experts say keeping in shape isn't about food deprivation, monotony, or following a tedious routine.

"It's pretty critical that people need to sort of start looking at their exercise as a balance between different forms of exercise for different priorities and goals," says Dr. John Berardi.

The fitness expert says the number one workout myth he hears is cardio exercise alone is the best way to improve fitness.

"It's sort of a remnant from the 1980's when cardio and aerobics were so popular," he says.

Dr. Berardi says as people age it's impossible to improve your fitness level and burn body fat with just cardio.

"People who jog or run every single year have to run an extra 40 miles to burn the same amount of calories they did the year before," he says.

That's why weight training is an important addition to a workout. A 50-50 split between the two is a good start.

Another common exercise myth is that weight training creates bulky muscles.

"In fact, what weight training does is it firms and tones muscles," says Dr. Berardi.

Research has shown resistance training can preserve lean muscle mass and increase your metabolic rate -- so burning fat becomes easier.

When it comes to frequency, Dr. Berardi says it's a myth that exercising three times a week is enough.

"It was a recommendation for people who weren't exercising now so that they could get started," he says. "The only problem is after a little while, it becomes too little."

Studies have shown five hours a week is ideal.

"The only way for the body to improve is to sort of force itself to do more or go a little harder," says Dr. Berardi.

And finally, there's the workout myth that weight training is for the young.

"I think people's work out priorities should be similar whether they're 20 years-old or 90 years-old," says Dr. Berardi.

The average person loses about ten percent of their metabolic rate each decade, and five pounds of lean muscle mass. Strength and resistance training can help stop that.

"You'll keep unwanted body fat off the body and keep the lean mass -- the muscle mass on your body which helps with healthy aging, and you'll be able to preserve your bones," says Dr. Berardi.

It's an essential routine for any age.

With a report from CTV British Columbia's Dr. Rhonda Low.