The Science of Motivation

Workouts and Intermittent Fasting

woman doing a hurdlers stretch on a mat at the gym

Hi and thanks for checking in!  Check out the post below and make sure to listen to your body when working out and doing IF.  They compliment each other well but don't push if things don't feel right.  As you get more comfortable with IF, you will gain a greater understanding of how much you can do during a workout.   - John



Figuring out when to workout and the types of workouts to do while intermittent fasting is probably in the top 3 most commonly asked questions. In short, you can definitely still do your regular workouts while doing intermittent fasting, it just might take a little tweaking as far as when you workout, including if you should do your regular routine while fasting or during the eating periods.

Eat After Working Out
Generally speaking, you want to try to schedule your workouts for shortly before you are going to start your eating phase. Of course, this may vary based on the type of workout you do and how long you fast for. The intensity of your workouts can also make a big difference. Some people who have extremely intense workout routines, like CrossFit, find that they need the boost in protein and carbs prior to a workout. If this is the case, you may be someone who should do your workouts during your eating phase, and not your fasting phase.

Use Caution With Cardio
If you do decide to workout when you are fasting, be careful with your cardio workouts. High-intensity cardio, like running or HIIT, can be a little hard on your body when you haven’t been eating for a prolonged period of time. Don’t schedule your cardio workouts on days when you are fasting if you do the 24-hour protocols. If you are doing a 16:8 split, then you want to do cardio after you have entered your eating period, at least allowing for a protein shake or something small and healthy before starting the rigorous routine.

Benefit of Working Out Fasted
There are a few reasons to try and schedule your workouts during fasted periods, as long as you aren’t feeling sick or faint. They include:

Great Fat Burning – Intermittent fasting is already helping you to burn more fat, so why not increase it a little bit? You might be able to increase how much fat you burn just by doing your workouts while you are fasting.

Easier on Stomach – Exercising while fasting can also help with digestion issues. Many people find that eating shortly before or after a workout makes it harder to digest, leading to a variety of stomach problems.

Lowers Hunger – Fasted periods can be hard to handle, especially if you are accustomed to eating every few hours. One great way to decrease the hunger pangs is to workout in the middle of the fasted stage. This helps prevent you from eating when you’re not supposed to be.

Check out the next post in the IF series:  Intermittent Fasting Do's and Don'ts