If the search for ultimate fitness came down to either cardio exercise or strength training, which would be the better choice? The answer may surprise you.

People work out with different goals in mind.  Some are looking for weight loss, some want cardiovascular fitness and some want to tone and build muscle. A complete fitness plan includes both cardiovascular and strength training but each has its benefits.

What are those benefits? 

  • Strength (weight or resistance) training. According to the Mayo Clinic, muscle mass naturally decreases with age. If you don't do anything to replace the muscle loss, it'll be replaced with fat. Weight training can help you reverse the trend at any age. As your muscle mass increases, you'll be able to work harder and longer before you get tired. You'll maintain joint flexibility, increase bone density and better manage your weight."  The more muscle mass you have the less body fat you'll store. Muscle burns more calories than fat. 
  • Cardio Exercise. The Mayo Clinic also clarifies the benefits of cardio (aerobics). "Aerobic exercise causes you to breathe faster and more deeply, which maximizes the amount of oxygen in your blood. The better your aerobic fitness, the more efficiently your heart, lungs and blood vessels transport oxygen throughout your body. The bottom line? It's great for your heart, lungs and long-term health and burns calories.

Miriam Nelson, author of "Strong Women Stay Slim" and director of the John Hancock Center for Physical Activity and Nutrition at Tufts University is quoted in the Wall Street Journal. Nelson says, "The calorie-burning debate gets complicated quickly. You are probably burning more calories when you are actually moving a heavy weight than when you are doing aerobic exercise. But you are taking breaks; so over 30 minutes the actual number of calories burned doing strength training will be less. You are [also] limited in the amount of strength training you can do. But you can do cardiovascular exercise every day." The American College of Sports Medicine (ACSM) advises no more than two to three weight-training sessions per week.  Nelson says, "Ideally, you want a combination of moderate to vigorous aerobic exercise and moderate-intensity strength training. But if vigorous aerobic exercise and vigorous weight training went head-to-head for calories burned, vigorous aerobic exercise would win."

ACSM says that resistance training alone does not enhance weight loss but may increase fat-free mass (muscle), increase loss of fat mass and is associated with reductions in health risk."

The Centers for Disease Control and ACSM both use the Compendium of Physical Activities Tracking Guide to determine how much physical energy specific activities require.  They're measured in METs (metabolic equivalent of task). The more METs, the harder the activity and the more calories burned.  Minute for minute - cardio burns more calories than weights.

  • Fast, swimming - 11 METs
  • Running a 12-minute mile - 8METs
  • Weight lifting - 6METs
  • Circuit training - 8 METs

Instead of asking which is better, cardio or weights, plan your workouts to include both.

Circuit training provides a combined strength/cardio workout by moving from weight to cardio equipment quickly for 30 minutes or more. Add in additional days of cardio for overall fitness and maximum calorie use.