What is the reason for fasting and training fasted?
Hormones such as noradrenaline, adrenaline and growth hormone increase after fasting for a certain period of time. After 12 hours of fasting, gastric emptying has taken place and your body is switching to fatty acids for energy instead of using glycogen.
Our fat cells have two receptors namely alpha- and beta-adrenergic receptors.
Increased expression in the adipocytes (fat cells) of alpha 2 vs beta-adrenergic receptors leads to obesity. You want as little alpha receptors as possible, or a constant inhibitor for it, you also want to predominantly activate beta receptors in order to overrule alpha 2 receptors.
– Alpha-adrenergic receptors have an anti-lipolytic effect, which allows the transportation of fatty acids into the fat cells which then increases fat content. And insulin actives these alpha receptors.
– Beta-adrenergic receptors on the other hand, allows for the transport of fatty acids to move out of the fat cells through the process called lipolysis. We want this process to occur as this is how we decrease fat.
So as you can see, insulin (caused by eating), activates alpha receptors and inhibits lipolysis, while fasting increase catecholamines and lowers insulin which leads to increased lipolysis (the burning of fat).
And we want to active lipolysis as it breaks down fat, or how else will we shake off the fat?
Next off, let’s combine these great benefits of fasting, with fasted weight training and find out what more results we can benefit from.
Catecholamines enhance your workout by increasing contractile strength, oxygen consumption and heart rate (better blood flow to the muscles), as well as lipolysis which helps to provide energy to the muscles by increasing free fatty acids.
Let’s compare catecholamines in fasted training with fed training.
Adrenaline pre to post-workout (0.10 – 0.26µg/L)
Noradrenaline pre to post-workout (0.24 – 0.70µg/L)
Adrenaline pre to post-workout (0.10 – 0.13µg/L)
Noradrenaline pre to post-(0.29 – 0.63µg/L)
But that’s all just theory. The truth is, that the studies out there claim that there is no added benefit to fat loss when exercising in a fasted state vs a fed state and can even be detrimental.
Here’s my solution.
While doing intermittent fasting, a few hours before the fast ends, take BCAA or HMB supplement to ensure you don’t go catabolic. Both these supplements are highly anti-catabolic. Then perform you exercise, and then afterwards, take your BCAA or HMB supplement again. Stay fasted after your exercise session. Fat burning will be significantly elevated post-exercise, and staying fasted will prevent that fat burning from being lowered by eating food.
The supplements will help you stay anti-catabolic and you will be burning lots of fat fast. Fast about 1-3 hours after that session before eating.
If you want to combine fasted cardio and weight training, read more here on how to do so.
The other cool thing about catecholamines is that it boosts testosterone production as well as power and provides tons of energy for your workout.
If you’re scared of doing fasted training because you’re concerned about not having energy for the workout or not getting as good hypertrophy, then read more about that here and here.