How to Exercise Safely During Intermittent Fasting


You’ll find someone who does intermittent fasting (IF), while maintaining their exercise routine, on any social media platform.

Although the IF craze seems exaggerated, this lifestyle is not new. Anecdotal and solid research is available on how to make IF work, especially if you plan to exercise while doing it.

Find out what experts have to say about safe and effective fasting exercise.

What are the pros and cons of exercising during a fast?
Before you start IF or fasting for any other reason, you should consider the pros and cons of fasting.

Research has shown that fasting while exercising can affect muscle biochemistry, metabolism, and insulin sensitivity.

Research supports eating right away and exercising immediately after. This is especially important for people with metabolic syndrome or type 2 diabetes.

Do you think the possibility of burning more fat sounds like a win? There’s a downside to this fast-growing cardio trend.

Amengual says that your body can start breaking down muscle to use protein as fuel while exercising in a fasted condition. She adds that you are more likely to hit the wall and lose energy, so you won’t be as able to exercise as hard or perform as well.

Priya Khorana (EdD), a Columbia University nutrition educator, says that long-term intermittent fasting is not ideal. She adds that “your body can deplete itself of calories, energy, which could eventually end up slowing down your metabolism.”

Fasting and effective gym sessions
There are some things that you can do to make you IF workout more effective.

1. Timing is everything
Christopher Shuff, registered dietician, says that there are three things to consider when you want your fasting workout to be more efficient: should you exercise before, during, or after your fueling window?

The 16:8 protocol is a popular method for IF. This concept involves eating all food within an eight-hour window, then fasting for 16 hours.

He explains that working out before the window is best for people who can perform well on empty stomachs and want to maximize post-workout nutrition. Shuff recommends that you exercise during the day for maximum performance and recovery.

2. Based on your macros, choose the type of exercise you want.
Lynda Lippin is a certified personal trainer and master instructor in pilates. She says it’s crucial to pay attention to what macronutrients you consume before and after you exercise.

She explains that strength workouts require more carbs the day before, while cardio/HIIT [high-intensity interval training] can be done on lower carb days.

3. To build and maintain muscle, eat the right foods after a workout
Dr. Niket Sonpal suggests that the best way to combine IF and exercise is for your workouts to be done during your meals so that your nutritional levels are high.

He adds, “And if your body does the heavy lifting, it is important to have protein afterward to aid in regeneration.”

Amengual advises that you follow any strength training with carbohydrates and approximately 20 grams of protein within 30 seconds after your workout.

How do you safely fast while exercising?
How safe the program is to maintain over time will determine how successful any weight loss or exercise program is. You must stay safe if your ultimate goal is to lose body fat and improve your fitness while doing IF.

You can eat a meal that is close to your high- or moderate-intensity workout.

Here is where meal timing plays a key role. Khorana suggests timing your meal to coincide with a high- or moderate-intensity workout. Your body will have some glycogen reserves to fuel your workout.

Keep hydrated
Sonpal reminds us that fasting does not mean we have to stop drinking water. He recommends drinking more water during fasting.

Keep your electrolytes up
Coconut water is a good source of hydration with low calories, according to Sonpal. Coconut water replenishes electrolytes and is low in calories. It also tastes good. Gatorade, sports drinks, and other sugary beverages are best avoided.

Reduce the intensity and length of your workouts.
You should take a break if you feel lightheaded or dizzy from pushing yourself too far. It is important to listen to your body.

About The Author