Fasting for cyclists
On fasted rides fat is utilised as an energy source.
Fasted rides train the body to use fat stores as fuel.
Cycling in the fasted state does result in a greater proportion of fat being used for fuel.
During long rides your muscles are coaxed into a higher level of fat burning.
This is appealing for performance reasons as this uses less muscle glycogen.
In the most abundant fuel source of adipose fat thousands of calories of energy are stored.
Fat droplets that reside in our muscle fibers can provide 2,000 to 3,000 calories of fuel.
However, one is always burning both carbohydrate and fat when cycling.
The carbohydrate fuels that one burns during training are muscle glycogen and blood glucose.
On endurance training rides for several hours at very low intensities such as 25 to 40 percent VO2 Max, adipose fat releases fat into your bloodstream and is the main fat fuel supply.
Increasing intensity to 40 to 65 percent of VO2 max keeps the flab fat burning, but also turns on muscle fat burning.
At this exercise intensity, about half of energy is supplied from fat, and the other half from carbohydrate.
Turning up the intensity to 70 to 80 percent of VO2 max does turn down fat burning a bit, as blood glucose and muscle glycogen can more quickly meet the need for faster fuel supply.
Read more at Fasting for cyclists in VeloNews