Fasted Cardio - Is it for you?
I spend a lot of time preaching about why its important for everyone to commit to one goal; fuel for weight loss or sports performance. It does not mean you won’t accidentally improve both, but it is important to pick your battles. Our bodies are designed to maintain balance via homeostasis and trying to make too many changes at once will ultimately lead to exhaustion and burn-out rather than robust health.
After all, whether you’re shooting for a PR or fat loss, we all want to be robustly healthy and feel energetic.
Enter fasted cardio. Friend or foe?
Fasted cardio gives our body a chance to mimic fasting, as our body’s energy demands are increased at at time when there’s minimal sugar stored in the liver. Fasted cardio forces our body to create its own sugar stores via gluconeogensis (read: breaks down fat stores), as well as enhances insulin sensitivity (read: helps us clear sugar from our bloodstream faster so we can get back into fat burning mode after eating a meal).
This is helpful for both the athlete with sports performance goals as well as those seeking fat loss.
Fasted runs or cardio allows the athlete to learn how to push themselves further and harder before “hitting the wall.” This concept of training low (low carb) and racing high (high carb) has substantial evidence to suggest that it helps your body more efficiently utilize carbs on hard training days and during competition. In essence, training fasted teaches your body how to better handle the phase of training when your carbohydrate stores are dwindling and your body is using more lactic acid for fuel. You can push harder and longer before experiencing that dread “hit the wall” feeling.
Likewise, fasted cardio also is beneficial for those seeking fat loss, especially when paired with a pre-exercise cup of black coffee or tea, as caffeine accelerates fat burning mid-fasted-workout. Fasted cardio not only is thought to increase fat-burning during the fasted-workout itself, but assists in creating a more “insulin sensitive” body long-term. The effects of being insulin sensitive make it easier for you to stay in a fat burning mode everyday with the added bonus of fighting against diabetes.
What counts as fasted cardio??
Whenever you’ve gone 8+ hours without food the stored sugar in your liver becomes fairly depleted. Engaging in low or moderate intensity cardio, such as a run or elliptical, for 30+ minutes allows your body to reap the benefits of fasted cardio. Athletes should strive to exercise for 60+ minutes in this state to truly practice stalling the “hit the wall” feeling.
If you’re in a time crunch but want to practice fasted cardio, doing HIIT workouts for <20 minutes also can help your body become more insulin sensitive.
Fasted cardio is a powerful tool for everyone.
Simply choose a minimum of 1-2 days a week when you can train early morning, before breakfast. Drinking water, coffee or tea without any calories from milk or sugar will not break your fast. Just remember that the fasted state is not the best time for training runs/workouts when speed or weight are being challenged. Carbs are great for workouts where you’re competing or trying to push your limits, while fasted cardio is a great tool for fat loss or to increase endurance.