Reality Check for the "I do cardio to lose fat" crowd

Reality check for the “I do cardio to lose fat” crowd

Low intensity cardio, which is the preferred form of “fat burning” exercise, is actually the least effective method to burn body fat. You’ve heard it over and over that if you do cardio your metabolic rate will increase and this will cause you to burn more calories from fat. Not true. Frequently performed low intensity exercise, such as walking and jogging, does NOT raise metabolic rate; it actually lowers it.

There are four well-controlled, inpatient, metabolic ward studies (published between 1982 – 1997) that clearly show a significant reduction in resting metabolic rate (your metabolism) when overweight subjects burned 300-600 calories/day while doing endurance (low intensity) exercise for several weeks at a time (1). So what does this mean? This means that frequent bouts of low intensity exercise can shrink muscle tissue which will decrease the amount of energy you burn; this side effect can lead to fat accumulation. This may not be the case for lean athletes, but the evidence is clear that low-intensity cardio is not an effective means to lose body fat for most overweight and obese people.

The most effective exercise protocol for increasing metabolic rate is high intensity strength training. Due to the glycogen depleting and muscle building effects of strength training, slight increases in resting energy expenditure are possible. The process of repairing and building muscle tissue is metabolically expensive and requires extra energy. For each pound of muscle you gain, you increase the amount of energy needed. These energy estimates vary from as low as 7 calories/ day up to 35 calories/day to maintain 1 lb of muscle; this doesn’t sound like much, but in the long run it adds up. Plus, the real fat loss benefits occur due to the improved insulin sensitivity and lowered insulin levels associated with a well-designed strength training program.

If you want to lose fat, you MUST build muscle tissue by implementing a well-designed strength training program.

1. Jeff Volek, PhD and Stephen D. Phinney, MD. The Art and Science of Low Carbohydrate Performance. s.l. : Beyond Obesity, 2012.