The Best Time to Work Out to Burn Calories on an Empty Stomach

Working out on an empty stomach is an old-school bodybuilding trick said to force your body to burn more calories. The tactic continues to be controversial because of its potentially harmful effects. There is a serious risk of injury, nausea, dizziness and/or fainting, especially for the novice trainee. It is recommended that you experiment for yourself to see if this methodology is right for you, but do so with caution. There are a handful of things you need to consider when choosing the best time to work out to burn calories on an empty stomach.

  1. Fasted Training

    • The controversy over so-called “fasted training” has raged on for a very long time. On one side, proponents claim that it burns fat better because your body must tap into its fatty acid stores for energy. Critics point to the potentially harmful effects of the stress hormone cortisol, which can slow fat burning, erode muscle mass and even promote fat storage, according to “The Cortisol Connection.” Should you choose to experiment with fasted training, you must remember that it is not a technique intended for beginners. Advanced trainees, more used to the intense rigors of constant training, may find it easier to adapt to working out fasted.

    Upon Waking

    • The best time to work out to burn calories on an empty stomach is when you first wake up. There is no other time during the day when you will have abstained from eating for anywhere close to the seven or eight fasted hours of sleep. One way of using this technique is to do some form of cardiovascular exercise immediately after waking to burn extra calories, presumably directly from body fat. Trainees may find this far easier than attempting fasted resistance-training workouts. Keep in mind that even in a fasted state, your body still has access to carbohydrates, known as glycogen, stored in the muscles and liver.

    Pseudo-Fasted Training

    • Another way to get a “fasted” workout on an empty stomach is to time your training for three to four hours or more after your last meal. For example, if you plan on hitting the gym at 8 p.m., you might have your last meal at 4 p.m. The idea is to allow your body to burn the majority of the calories from your meal prior to beginning the workout. Obviously, abstaining from eating for six to eight hours during the day would be uncomfortable and impractical. However, that would be the only way to effectively simulate the effect of true fasted training.

    Protecting Muscle

    • Using muscle-protective supplements may help you get the benefits of fasted training without suffering the supposed consequences of high cortisol levels. For example, the BCAAs, or branched-chain amino acids, keep cortisol from breaking down muscle protein for energy. They are considered special amino acids -- the building blocks of proteins -- because they are metabolized by muscles directly and provide a source of energy for their function. You can find L-leucine, L-isoleucine and L-valine -- the BCAAs -- in powder or pill supplement form. Consider taking 5 to 10 grams of BCAAs immediately before and/or during your fasted work out to help protect your lean muscle mass.