During my intermittent fasting and extended fasting days I do have less of that “umph” energy to work out. However, I still am able to move my body during yoga, cardio, weight training, long walks and hiking. Since weight loss is my goal, I do not push myself beyond a tolerable limit. If performance is your goal while fasting, there is a different protocol to this. During the period of changing burning sugar to fat, there is a definite notice in performance which can last up to 2-3 weeks.
Many people assume it will be difficult to exercise while fasting and yes, exercise demands extra energy from the body. However the process of using extra food energy (fat stores) during a fast remains the same. The body starts using glycogen, the sugar stored in the liver. Since there is extra demand for energy during exercise, glycogen runs out sooner. This is that feeling of “bonking” people experience. The switch must now move using sugar to fat. Your body generally carries enough glycogen for around 24 to 36 hours before running out.
Choose a movement pattern that you enjoy. Cardio does not have to be running. Lift heavy things a few times a week to maintain muscle mass. The myth that you will lose muscle mass during fasting is based on the premise of not lifting weights. We only lose muscle mass if we do not engage our bunz and gunz. Increased growth hormone is a side effect of fasting, so take advantage of tapping into that muscle loving increase!
But even when our glycogen runs out, we’re still carrying vast amounts of energy in the form of fat. During fasting the switch from burning sugar to fat is switched. This is one of the reasons why counting calories does not work. It doesn’t drain the mucky fuel of sugar to turning on the switch to burn fat. Yes, we can do both at once, but the primary fuel source needs to be fat, especially if you want to lose weight.
If losing weight is one of your main health goals, working out on an empty stomach in the morning before any food can help achieve this. Your performance might not be as strong or quick as before, but you are training your body into learning how to utilize the fat stores on your body as energy. Exercising in the fasted state trains your muscles to burn fat. Muscles adapt to whatever energy source is available. Have you seen endurance athletes hit the wall? They have not adapted their body to use fat stores, generally relying on goo and gel blocks to get them by. When we deplete our glycogen through fasting, or muscles learn to become more effective at burning fat. After training in the fasted state, muscle fibers show increased available fat.
Storing more energy in the form of fat significantly outweighs storing sugar as fuel. Since your body is relying on fat stores, there’s no shortage of energy during fasting, and you can and should do all of your usual activities. The combination of low insulin and high adrenaline levels created by fasting stimulates the breakdown of fat for energy.
Exercise tips after switching from a sugar burner to a fat burner:
You can train harder due to increased adrenaline
You’ll build muscle faster due to increased growth hormone
You’ll burn more fat due to increased fatty acid oxidation
You might find that you will be less sore after a workout
Train harder, build muscle, burn fat