So your trainer or coach (or fitness friend) has suggested you try pre-breakfast cardio to help shed a few extra pounds. You may think she’s gone crazy, however there’s actually a method to the madness of early morning sweat sessions. The body’s physiological response to food and training is an intricate science, one we can manipulate to enhance fat mobilization and get closer to our goals. But before you jump out of bed and start running sprint drills, read on. Proper execution of this strategy means understanding the science behind it.

The body exists between two states, “postprandial” or the fed state, and “post-absorptive” or the fasted state. During the postprandial state, the body has food stores to burn, so it shuts down its fat burning mechanism and relies on the energy provided from the meal. Performing fasted cardio provides a way around this problem, leaving the body primed for fat burning.

Women and men experience fat loss and muscle gain very differently due to our physiological makeup. “Stubborn” areas for women and weight typically occur in the hips, thighs, butt and lower abdominal region. While you know you can’t spot reduce, which refers to targeting a specific area for weight loss, research indicates that fasted cardio increases blood flow to the abdominal region, which in turn can help to slim out these areas.

Now for the heavy science: Catecholamines are chemicals that break down fat cells by attaching to fat receptors in your body. There are two main fat receptors, known as Beta1 and Alpha1. Alpha1 repels these catecholamines, and Beta1 receptors are drawn to it. Increased bloodflow through fasted cardio can help deliver more catecholamines to these aforementioned stubborn areas and increase your chances of fat loss.

This topic is often debated in the fitness industry due to potential concerns over muscle breakdown and its true fat-burning potential. Research indicates that when implemented properly, this method does in fact alter body composition, but individual goals and health concerns, especially those that deal with blood sugar issues, should discuss this method with their doctor.       

First, let’s be clear that fasted cardio is not a magic solution to fat loss. It requires a proper nutritional strategy, along with utilizing the correct exercise intensity, in order to make significant changes.

For starters, fasted cardio workouts are not endurance sessions. Keep these sessions to 45-60 minutes maximum and as soon as your session is over, make sure to eat.

Keep the intensity of your cardio between 60-65% of your maximum effort to avoid spiking your cortisol levels. When intensity increases above this level without food in the system, a crossover state occurs, where the body releases glucose and cortisol, undoubtedly causing muscle breakdown.

Perform fasted cardio shortly after waking. You do not want to be awake any longer than 90 minutes before eating. Ingesting a small amount of amino acids and glutamine 15-30 minutes before training can also help to ward off the potential for catabolism (muscle breakdown). A profile of five grams of branched chain amino acids (BCAAs), along with five grams of glutamine and five grams of essential amino acids should suffice.

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