Fasted Cardio and HIIT/MIIT

Fat loss is a particularly difficult idea for most people to grasp. Most individuals will find if they focus primarily on cardio, then they will lose weight. These same individuals will also find that they did not tone up the way they wanted to. Cardio fasting has been my go to method for losing fat while maintaining muscle tone. 

Before one can understand the construct of fasted cardio, they must first understand what a fasted state means. When we eat our bodies digest the food and break it down into its bio-available state I.e. glucose, fatty acids, amino acids (blog post coming soon). The small intestines will then absorb these by products and transfer them to our cells utilizing the hormone insulin. This will cause a spike in your insulin levels while the nutrients are traveling through the body to the appropriate cells. This is known as a “fed” state.  

When your body has finished transporting the nutrients to the appropriate cells, insulin levels return to baseline levels. This is known as a “fasted” state. The size of the meal and how easily digestible (shake/smoothie lovers are winning here) the meal is will affect how long it takes the body to return to a fasted state.  

Cardio is simple enough to understand, but there are different levels of cardio. Low intensity, moderate intensity, and high intensity. They all have their benefits and draw backs.  

Low intensity cardio (walking on a treadmill at an incline for 60 minutes) has been shown to burn more calories DURING the workout, but not POST workout.  

Moderate intensity cardio (Faster paced runs) has been shown to burn more calories than low intensity exercises DURING the workout AND POST workout.  

High intensity cardio has been shown to burn less calories DURING the workout, but more calories than low intensity cardio POST workout.  

Moderate intensity to High intensity interval training (HIIT) is my favorite form of cardio. It is short, fun, and the benefits continue after the workout is finished. 

Benefits of HIIT or MIIT 

1. Elevated metabolic rate for the next 24 hours.
2. Improves insulin sensitivity, which allows for better digestion of micronutrients.
3. Allows muscle to burn fat more easily.
4. Increases the production of the human growth hormone, which aids in fat loss.

The real benefits of fasted cardio (in combination with MIIT or HIIT) are the post workout benefits described above. Take advantage of these favorable insulin and hormone levels and make sure that your nutrition is on point. Consume a high protein meal post work out (and throughout the day) and replenish your glycogen levels knowing that your body will continue to burn oxidized fat for the next 24 hours.  

It is a lot easier to get fasted cardio done in the morning when you first wake up. That is because you are already in a fasted state. Take advantage of this window and get the day started with some cardio and then complete your weights and conditioning later in the day when you are in a fed state.  

The biggest draw-back of cardio (especially HIIT or MIIT) is that the body can not oxidize fat quickly enough to use it for energy. That means the body will turn to the glycogen stores in the muscles for energy. To prevent this from happening I suggest drinking branched chain amino acids (BCAAs) before and during the workout. The following methods are suggested as well: 

1. Eat a high protein diet.
2. Stay with a consistent weights and resistance training program.
3. Adjust caloric deficit to 15-25%.

Fasted cardio is a great construct that has been shown to stimulate lasting change. This method is especially effective for lean individuals who have some stubborn fat areas that need a little extra work to flatten out. Take advantage of your fasted state in the mornings and start the day off at a deficit and reap the benefits for the next 24 hours.