Engaging in fasted exercise involves exercising without eating. For most people this means eating the night before, going to bed and then waking up and working out before having breakfast, but could also be evening exercise if you have not eaten in the previous 10-12 hours. Food is used to provide glucose to the cells in the body, which is then converted to energy to be used for exercise. When there is no new source of glucose available however – from not having recently eaten – the body relies on other methods of energy extraction and this can be very advantageous for performance and physique.
Burn More Fat
The theory is simple: your body’s default source of energy for exercise is glucose or glycogen. Glucose is readily available from your recent consumption of carbohydrates, and glycogen is the stored form of glucose from carbohydrate metabolism. When you exercise fasted however, your body has no glucose to use and the body’s glycogen stores are relatively depleted. This means instead, the body uses its next most accessible source of fuel: fat. Whilst the specifics vary for each person, depending on how efficient your metabolism is, how long since your last meal, the exercise intensity and how much the body is used to fasted fitness, there is evidence to support increased fat burning potential when training in a fasted state.
Boost Brain Power
And just as the body reverts over to burning fat for fuel to allow you to physically perform, it also uses fat for fuel to sustain your mental performance and cognitive function. The increased presence of ketones in the body acts as an ideal fuel for the brain, improving mental clarity, boosting concentration and helping sustain the brain through demanding mental tasks such as exercise. Indeed, success in athletic performance often stems from mental resilience and toughness, and these two have been shown to be highly connected. Boosting how efficiently your brain accesses and uses energy and increasing mental stamina is hugely beneficial to athletic performance and is also known to increases levels of BDNF, a naturally occurring growth hormone that is responsible for neurogenesis and is associated with increased intelligence, mood, productivity, and memory along with decreased risks of neurodegenerative diseases like Alzheimer's & Parkinson's. However there is an exponential increase in BDNF if we exercise fasted, so a great to strategy to employ if you also want to protect yourself against depression and dementia.
Increases Insulin Sensitivity
In addition to burning fat for fuel, fasted exercise also increases the body’s sensitivity to insulin. Insulin is the hormone released in response to glucose entering the bloodstream which is released to help regulate your blood sugar level, and prevent it from staying too high or dropping too low. When you consume food after a fasted workout, where your insulin levels are low, the insulin responds more effectively because it hasn’t been hovering in a low-grade response for a few hours. This is of great benefit as decreased insulin sensitivity can lead to insulin resistance, which is a precursor to diabetes for some individuals.
Understanding your body, your goals and how you respond to exercise is a key part in identifying whether fasted exercise is for you. Visit Ancient + Brave to learn more about the products we offer to improve your fasted exercise performance and give it a try to experience better brain power, increased fat burning and improved insulin sensitivity.