Has a personal trainer ever told you to fill up before a workout?
I don’t know about you but early in my fitness journey, I was always told I had to eat something before working out.
I never wanted to. I always felt stuffed and sluggish during my training session.
Many believe having a pre-workout meal helps them achieve optimal performance during their workout.
There are all types of pre-workout meal plans highlighting the importance of eating before working out.
Like the food industry, the fitness industry wants everyone to consume their latest supplement or smoothie.
While not eating before working out is not for everyone, there are massive benefits gained from working out in a fasted state.
You become more sensitive to insulin and allow the human growth hormone to help you burn fat and build muscle.
If you practice intermittent fasting daily, working out fasted will increase your sensitivity to insulin.
Your insulin is at baseline while fasting and eating before working out causes your insulin levels to rise. The goal for you should be to restrict the spike of insulin as much as possible(eating one to two times a day).
In his article, Fasted Training For Superior Insulin Sensitivity And Nutrient Partitioning Martin Berkhan who popularized the Leangains method of fasting cites a study done on males that were lean and healthy.
In the study there were 3 groups:
- The C Group-practiced fed training with a carb-rich pre-workout meal with a maltodextrin enriched breakfast.
- The F Group-practiced fasted training. They received the same meal as the C group but later on in the day.
- The Control Group- They received the same meal as the C and F group but did not work out.
After the study, the results concluded that the F group had better glucose tolerance and insulin sensitivity (which goes hand in hand) than the C group.
However, the C group did see some improvements of insulin sensitivity but not as much as the F group did.
You improve your overall workout performance.
Working out in a fasted state also allows the human growth hormone to work in your favor.
When you eat the release of the human growth hormone is restricted by the rise of glucose in your system.
Even if you don’t work out in a fasted state, delaying your first meal by a few hours allows you to have better physical function and longevity.
A study cited in the Science Daily article, Routine periodic fasting is good for your health, and your heart highlights the fact that after a 24 hour fast, males HGH production was up 2000% and females 1,300%.
You also will receive a testosterone boost while working out in a fasted state. Testosterone increases libido, muscle mass, and energy levels in men and women.
Working out in a fasted state allows HGH and testosterone to work in tandem providing you the best environment for burning fat and building muscle.
Personally, I have tested working out in a fasted and fed state. I found that at first working out in a fasted state was weird and I had no energy.
After a few fasted workouts I saw a vast improvement. My energy levels skyrocketed and I increased fat loss and muscle growth.
Now when I workout in a fed state I feel sluggish and my performance is stunted.
Keep in mind that staying hydrated and eating a diet of whole minimally processed foods gives you the best results working out in a fasted state.
Working out in a fasted state trains your body to burn fat more efficiently.
In the study with the lean healthy males, VO2max (maximum uptake of oxygen was also measured along with FatMax ( maximal rate of fat oxidation).
The C group (fed workouts) saw an increase of VO2max. This was because the C group had a larger amount of glucose available to maintain endurance.
In the F group (fasted workout), they naturally experienced a higher level of FatMax.
There was no change of VO2max or FatMax in the C group.
The longer you train in a fasted state, the more fat adapted your body becomes. This means that your body is able to burn fat more efficiently over time.
The lack of glucose in your system allows this to happen.
Over time along with having a higher FatMax, I suspect F group would see an increase of Vo2max as they become more fat adapted.
I encourage you to experiment working out in a fasted state. Whether you do more compound movements or HITT based workouts, the results will stun you.
If you are new to fasting and want to learn more, The Ultimate Beginners Guide to Intermittent Fasting will get you started.
Fast daily for a while before working out in a fasted state. Once you start working out fasted it’s hard to go back.
Discover what healthy foods to eat after your fasted work out. The “Break” Fast Food Guide will give you great ideas.