You may think you need food to fuel your workouts, but you are wrong.
Recently, the advice that suggests loading up on carbohydrates before exercise has been called into question. Yes, consuming carbs before exercise can increase performance in certain fields like sprinting and sports that use power movements, but it also stops the body from using stored body fat for energy, which means you are less likely to reap the reported fat burning benefits.
So, if you exercise to stay trim, going ‘fasted’ is the more effective option.
What does fasted mean?
Over the course of the day you go in and out of fed and fasted states. The fed state lasts for about four to six hours after your last meal, during which time your body releases insulin to lower your blood sugar, proteins and fats are absorbed by the digestive system, and glucose is transported to the muscles to be used as energy (glycogen).
Six hours after eating you enter the fasted state. Glucagon is released to keep your blood sugar at normal levels. Your body starts to break down adipose (fat) tissue into free fatty acids, which can then be converted into a form of energy known as ketone bodies. In layman’s terms, you’re burning fat for energy.
As soon as you start eating, the process is halted. Insulin now inhibits the breakdown of fatty acids, leading your body to burn the sugars you’ve just ingested. The fat burning stage is over.
If you think about it, this all makes perfect evolutionary sense. When food wasn’t as readily available as it is today, holding on to stored body fat was crucial for our survival. We evolved to last a long time between meals.
Today, food is in almost constant supply – but our bodies are still physiologically the same as they were tens of thousands of years ago. If we eat all day, we never tap into our bodies’ natural ability to burn stored body fat for energy.
Studies demonstrate that a bout of aerobic exercise performed in the fasted as compared with non-fasted state increases the reliance on fat and subsequently reduces the reliance on carbohydrate as fuel during exercise, with several publications showing that fasted exercise oxidises (burns) around 20-30pc more fat.
If you’re exercising to lose weight, it’s a no brainer.