There’s a lot of conflicting information when it comes to working out in a fasted state. Some schools of thought say it’s ok to workout fasted as long as you’re doing cardio and not strength training.
Others say that it’s perfectly fine to workout fasted doing cardio or strength training.
But the key is to figure out what works best for you. If you feel as though you need some fuel before working out, do so.
But keep in mind that eating before working out makes your body burn glycogen which is stored sugar in the liver.
If you workout fasted you have a better chance of burning your fat stores. This is especially true if you follow a low carb diet.
Your body will always burn its glycogen stores before fat.
Slowly build to working out fasted
If you’re new to fasting it’s best to work out after eating. Even if it’s a small meal you’ll have an easier time adjusting to your fasting protocol.
As your body becomes used to being in a fasted state you can start to test and see if working out fasted is better.
The benefits of working out fasted include:
- Increased human growth hormone (HGH) levels which aids in fat loss and muscle growth.
- Better performance (once your body becomes accustomed to burning fat)
- You have the potential to have a more efficient metabolism
One study examined the benefits of metabolic adaptations due to endurance exercise training in the fasted state.
In the study:
- 20 healthy males were assigned to two experimental groups for a 6-weeks. There was the fasted group (F) and the fed group who ate an ample amount of carbs before working out (CHO).
- All subjects were active previously and were told not to participate in any strenuous activity other than the exercises prescribed in the study.
- The F group did all training in the fasted state. The CHO group had a carb-rich meal 90 minutes before the training session.
- The study found that the F group had more muscular oxidative capacity. The F group’s blood glucose didn’t drop like the CHO group.
The study concluded to say that fasted training is a good tool for endurance.
Your body won’t lose muscle
Contrary to popular belief fasted training won’t inhibit muscle growth. The study I cited above, clearly points out that fasted training enhances physiological adaptations that can improve muscle growth and endurance.
If you are eating the proper amount of healthy calories per day you shouldn't worry about muscle loss while training in a fasted state.
In an article on The Fasting Method blog, Dr. Jason Fung a fasting expert points out a study small study done with athletes after a 3.5 day fast.
The athletes' strength, anaerobic capacity, and aerobic endurance were not affected after such a long fast.
Dr. Fung highlights the fact that the body simply switches from burning sugar to fat. You have far more fat reserves on your body. This provides an almost boundless energy source for you.
This switch is most effective if you allow a 2 week adjustment period. A low carb diet also helps the body burn fat more effectively.
Vary workouts and fasting schedule
If you have frequent strenuous workouts it’s best to keep an eye out on your caloric intake.
Fasting makes it easy to go into a caloric deficit which is good for most people. But with the goal of gaining lean muscle, proper nutrition, and caloric intake is key.
Every day doesn't have to be a long drawn out fast for you to see results.
Eat more on days when you workout hard. Consider shorter fasts on workout days especially if you’re new to working out fasted.
Fasted training is a great way to increase strength and endurance. It allows you to burn more fat over time. It’s one of the best ways for your body to enter a peak performance state.