Boost Your Metabolism, Build Muscle

By continuing to build muscle, firing up your metabolic burn during cardio and fueling up with clean meals, you can keep your metabolism at its highest no matter what age you are. Here's how to do it.

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When it comes to having a toned, lean body at any age, you know that the key is a revved metabolism that moves faster than your best friend at a Marc Jacobs sample sale. As an active gal, you already have an advantage over your sedentary friends: Those tight biceps, arms and abs you’ve been building in the gym mean you’ve got more lean muscle mass – a form of tissue that’s more metabolically active than fat and that helps you burn more calories throughout the day. Put simply, your fit habits put you a step ahead of the game.

Even as you get older, living the Oxygen lifestyle is the secret to keeping your metabolism revved. “Your resting metabolic rate drops two to three percent every decade after the age of 20, typically due to a loss of muscle mass” says Pamela Peeke, MD, a Pew Foundation scholar in Metabolism and Nutrition and author of Body for Life for Women. When you do the math, this means a four to six percent slower metabolism in your 30s and an even slower one once you hit 40 or 50. But by continuing to build muscle in the gym, firing up your metabolic burn during cardio and fueling up with clean meals, you can keep your metabolism at its possible highest no matter what age you are. Here’s how to do it.

Strength Train to Build Muscle

Strength training is the absolute best way to boost your metabolism because it helps you to build and maintain muscle. “Muscle mass is terribly important and is the one significant element of metabolism that can be changed,” says Peeke.

Lifting weights stresses and breaks down your muscles, which respond by building more muscle cells to compensate for the new loads being placed upon them. These new cells require energy, and burn three times more calories than fat cells, even at rest. “With a standard cardio workout, once your heart rate goes down, the calorie burning process stops,” says Juliet Kaska, an ACE-certified personal trainer and owner of JK Zen Fitness in Los Angeles. “But with resistance training the caloric burn continues for several hours as your body recovers from the workout.”

As an Oxygen reader, you’re already lifting weights, but there are many ways to jazz up your routine to make it more metabolically intense. For example, drop sets, supersets negatives and compound sets are all great techniques to put additional stress on your muscles, forcing them to use more energy and boosting your metabolism. And circuits will increase your fat-burning effect too. “Play with these techniques to continually give your muscles new stimuli and reasons to strengthen and grow,” says Kaska.

Changing your rep range is another great way to switch things up. Use heavy weights and low reps (six to eight) for a few weeks to help your muscles grow, then follow with two weeks of higher reps (12 to 15) and lower weight to build endurance. Increasing your strength-training stamina will help you hit the weight stack for longer periods of time, therefore burning more calories in the process. Also try changing the time of day you train. Though there is no research proving that a particular time of day is better metabolically than another for lifting, you might find you have more energy in the morning than at night, or vice versa. More energy equals better focus, and better focus equals more intensity and more energy expended (and that means you burn more calories too!).

Add Intensity to Your Cardio Sessions

Look around the gym and you’ll likely notice that many women still adhere to the Long Slow Cardio theory when trying to lose body fat: They set the treadmill to a light, steady pace and run through an entire hour-long episode of Glee. But numerous studies indicate that shorter, high-intensity bouts of exercise do more to spike metabolism and burn fat than longer, less intense sessions.

One Scottish study revealed that in just two weeks time, subjects were able to boost metabolism by doing intense 30-second cardio bursts. So instead of plodding for an hour on the treadmill or elliptical trainer, warm up thoroughly, then do five to 10 high-intensity, 30- to 60-second sprints with 30- to 60-second rests at a slower pace in between, suggests Kaska. “You’ll shorten your overall workout time and will boost fat metabolism for hours afterward.”

Fuel Your Metabolism with Clean Eating

In addition to your workouts, you know that nutrition is a vital piece of the metabolic puzzle – properly fueling your body with the necessary nutrients allows it to build muscle, metabolize fat and perform well in and out of the gym. As a clean-eater, munching on five to six small meals during the day already puts you on the right track. “To get your metabolism to work harder, you have to keep throwing small logs onto the fire,” says Robyn L. Goldberg, a registered dietitian in Beverly Hills and owner of And the more frequently you eat, the faster your metabolism and the more quickly you’ll lose fat and drop dress sizes.

But there’s more to the equation. What you eat is just as important, and when you’re talking metabolism, the key is protein. Those skinless chicken breasts and egg whites you’re including in your meals work to spike your metabolism in several ways. Not only are they superstar muscle-building foods, but they also have a thermogenic effect in your body. “Proteins take a lot of effort and calories to process,” says Peeke, and more than fat or carbohydrates. That means your body requires more energy to digest protein, and all that extra effort translates to more calories burned. As an active woman, reach for about one gram of protein per pound of body weight each day.

Lastly, make sure to avoid crash diets or drastically cutting your calories. While you might initially lose a few pounds, it’s a guaranteed way to send your body into survival mode, holding on to fat and slowing your metabolism. “For an average size woman, when you dip below 1,200 calories a day you can actually see negative metabolic changes and a decrease in metabolic rate,” Peeke says, adding that once your metabolic rate drops, you won’t be able to eat much without piling on some weight.

Think of your diet plan in the same way as your workouts: Approaching your meals with the goals of muscle-building and a boosted metabolic burn is the best way to get a body that stays lean, strong and healthy at every age.

Don’t Forget Your Rest Days

If you want to accelerate your metabolism, your rest days are just as important as your gym days. During off days, your body recovers and repairs itself, building more muscle cells to burn even more calories and boost your metabolic rate even higher. Continually exercising with no time off can lead to overtraining, which can cause you to become catabolic, literally eating the muscle cells you’ve worked so hard to add! Take at least one full day completely off from training per week, two if you’re working extra hard.

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