Improved fat burning
The logic goes – if you don’t give your body any fuel before a ride, it has to use its own body fat for energy. Is that true? Researchers from the University of Bath in the UK think so. They had a group of overweight men perform 2x 60 minutes of cardio. Once in the morning after a 12-hour fast and a second time 2 hours after eating a 650 kcal breakfast consisting of cornflakes, a toast, and orange juice. They found that expression of genes responsible for burning fat was substantially increased when exercising after a fast. They concluded that you’re not only burning more fat during, but also can enjoy long-term fat-burning benefits after exercising that way.
Improved growth hormone production
A study showed that 24 hours without food can increase the body’s growth hormone production up to 20x. That’s impressive! Why? Because growth hormone helps your body make new muscle tissue, burn fat, improve bone quality, and increase longevity. Proper sleep and regular weight training are known to help with that too, so make sure to get a good night’s sleep before your fasted ride to get the most out of it!
Improved glycogen storage
Studies also show that exercising while fasted increases the efficiency of muscle glycogen storage. This basically means that riding with no food in your stomach teaches your body to make better use of the glycogen stores you already have. And this carries over to your other rides too – your body will perform that much better when you do feed it.
Improved VO2 max
There are studies showing that riding on an empty stomach might help you develop one of the most important measures of fitness in endurance sports, your VO2 max! When your body uses a higher proportion of fat as a fuel, it needs to adapt by increasing mitochondrial density. This in turn improves your body’s capacity to take in and use oxygen during exercise.
Improved recovery
You can already see that with better growth hormone production, improved glycogen storage, and overall higher efficiency of your engine, fasted rides will also promote recovery. One study concludes that fasted endurance training may induce a quick re-activation of muscle protein translation (meaning faster recovery), compared to training after eating carbs.
