Which Burns More Fat: Cardio or Weights?

The common perception is weight training builds muscle and cardiovascular exercise burns fat. But the reality is not so clear cut. Weight training may burn less fat than cardio during exercise, but through various processes such as post exercise oxygen consumption, it can help you burn fat up to 48 hours after exercise, according to Len Kravitz, PhD, of the University of New Mexico.

  1. Guidelines

    • The Physical Activity Guidelines for Americans set by the Department of Health and Human Services recommends a minimum of 150 minutes of moderately intense cardiovascular exercise a week for weight control, which is exercise where you will have a noticeable increase in your breathing and heart rates. According to a study published in the October 2009 issue of the “Journal of Strength and Conditioning Research,” cardiovascular exercise at 60 to 80 percent of your maximum heart rate burns fat. If you are male, calculate your maximum heart rate by subtracting your age from 220. Women should subtract 88 percent of their age from 206.

    Considerations

    • Kravitz says progressively challenging cardiovascular exercise enhances your ability to burn fat, triggering certain physiological and metabolic adaptations that enhance fat metabolism. These include increased oxygen delivery that helps cells burn fat more efficiently and increased blood circulation, improving the delivery of fatty acids to the muscles to be used as energy. Cardio also increases the number and size of cell mitochondrion. The mitochondrion is the cells fat-burning furnace.

    Comparisons

    • Cardiovascular exercise and a combination of cardio and resistance training or weight training burn more fat than resistance training alone. But a combination of cardio and resistance training does not burn more fat than cardio alone, according to a study in the July 2012 issue of the “Journal of Applied Physiology." However, resistance training helps maintain lean muscle tissue, keeping your resting metabolic rate high. Loss of muscle tissue depresses your resting metabolic rate and reduces your ability to burn fat.

    After-Burn

    • Excess post-exercise oxygen consumption, or EPOC, occurs as the body continues to use oxygen at an elevated rate after exercise. It metabolizes fat for energy as it restores expended nutrients and returns to its pre-exercise state. Intense resistance exercise causes significant changes in the body compared to cardiovascular exercise. These changes include increased levels of lactic acid and circulating hormones. According to Kravitz, these changes prompt greater energy expenditure after exercise as the body works to return to its normal state.