This post may contain affiliate links. Please read our disclosure for more info.
Remember being told that “breakfast is the most important meal of the day?” Well, consider tossing that out the window in favor of intermittent fasting instead – you may experience higher energy levels, increased immunity, and even weight loss. It’s not for everyone, but it may be perfect for you and your health goals – it doesn’t hurt to try!
What is Intermittent Fasting?
Intermittent fasting is a period of voluntary abstinence from caloric consumption for certain periods of time – it’s not a diet, but rather a dieting pattern.
You will intentionally fast for a larger portion of your day, and only eat within a specified window of time (this is the opposite of what most of us do, where we are eating meals throughout the day, and only fasting for small windows of time between meals). When you’re in your fasting window, you can consume water, calorie-free tea, and black coffee.
Is it Okay to Exercise While Intermittent Fasting?
Yes (for most people).
Don’t attempt to run a triathlon or expect to max out your reps when you’re exercising in a fasted state, but do perform light to moderate cardio and bodyweight exercises. Stop immediately at any time if you feel week or dizzy, and remember to drink water.
How Does Intermittent Fasting Work?
A few factors are at play with Intermittent Fast (IF) that contribute to weight loss and overall health improvement:
1. Cell health: When undergoing fasting, cells are placed under mild stress, and they respond to the stress adaptively by enhancing their ability to cope with stress, leading to an increased resistance to disease.
In addition to this mild stress, cells in fasted mode will enter autophagy, which is essentially waste removal for the cells; it has proven to remove dysfunctional proteins that have built up within cell walls over time. Think of it like a juice cleanse for your cells.
2. Fat loss: When you don’t eat for 8-16 hours, your body must resort to fat stores for energy. In a fasted state, limited carbohydrate (glucose) availability causes your body to resort to facilitating energy production via fat oxidation.
3. Weight loss: Aside from your body relying on fat for energy in a fasted state, when you take on intermittent fasting, it is likely you will reduce your appetite.
Studies have shown that people who fast intermittently actually consume less calories in their eating windows within the day than they do when they don’t fast intermittently (the same meals were “counted” to compare calorie consumption: for example, if during IF the window for eating was between 6-10 PM, the same window of 6-10 PM was counted for on days that the subject consumed breakfast)
Can I workout in the morning while intermittent fasting?
The most common form of intermittent fasting will leave you without food in the morning, but the morning may be your favorite time to exercise. Or, you may want to take advantage of the benefits of exercising in a fasted state by doing so in the morning.
When you’re exercising in the morning in a fasted state, keep the workouts to low-impact and low-intensity.
Walking, jogging, light cardio, pilates, yoga, barre, cycling, bodyweight exercises, and/or a combination of a few of these are all excellent options for fasted exercises. Do not exceed more than 60 minutes of exercise when in a fasted state.
Is it hard to exercise while intermittent fasting?
When you first start fasting, you may wake up feeling incredibly hungry (whether you’re exercising or not!) It takes anywhere from 10-20 days to get past this, so it’s a good idea to exercise in ways that will help you distract yourself from this hunger.
Don’t try to do exercises that you know aren’t your favorite. Instead, opt for the activities you know that you enjoy, as you might find that you feel an even better mind-body connection practicing these activities on an empty stomach.
For example, if I am not a fan of jogging because I find it boring, I am not going to go for a morning jog on the days I’m fasting because I’ll will be incredibly cranky and frustrated the whole time!
Workouts to Try While Intermittent Fasting:
- Yoga: most practitioners actually prefer to practice yoga on an empty stomach – it provides a “clean” and “light” feeling that allows you to focus entirely on your breath and body’s movement. Many studios will offer early morning classes, but you can also check out our Free Resource Library full of workouts!
- Dance: dance in any form (if you enjoy it) is a fun activity that will make you completely forget about any kind of hunger. This can be in the form of ballet, barre, Zumba, hip-hop – anything!
- Tennis: if you’re an avid tennis player, a morning match will be a breeze when fasted.
- Walking (or light jogging): put your favorite podcast on and go for a leisurely (or not so leisurely) walk or jog, anywhere from 1-4 miles.
- On the treadmill: try walking on an incline (3.5 mph at an 8 incline or higher) – it’s actually been proven to burn more fat than jogging on a flat surface!
- Cycling: whether indoors or outdoors, great music coupled with a great ride will make you feel like you are literally gliding through air.
- Pilates: similar to yoga, practitioners often prefer an empty, “light” state of being
Workouts to avoid in a fasted state:
- Power lifting
- HIIT – classes such as OrangeTheory, Barry’s, etc.
Exercise routines to try while intermittent fasting:
If you’ve got 30 minutes:
- Take a 15-minute walk (1 mile) outside or 1-mile walk on an incline on a treadmill
- Spend 15 minutes with bodyweight exercises: core work, pushups, squats, lunges
If you’ve got 45 minutes:
- Take a 20-30 minute walk or jog (2 mile) outside or 2-mile walk on an incline on a treadmill
- Spend 15 minutes flowing through yoga vinyasas, or 15 minutes with bodyweight exercises
Here are a few of our favorite yoga routines that are just under 20 minutes, perfect to incorporate with a simple warm up:
- 10 Minute at Home Yoga Workout for Strong Abs
- 15 Minute Yoga Routine to Lose Weight and Boost Your Metabolism
- 20 Minute Full Body Yoga Workout for Beginners (+ Free PDF)
- The 20 Minute Yoga Routine Every Beginner Needs + Free PDF
If you’ve got 1 hour:
Check what classes are available in your area, go for a bike ride, or a long walk in the park. Recruit a friend to walk or bike with you, or go for a swim in the ocean or pool.
One of my favorite ways to do fasted cardio is actually spending an hour on the treadmill walking on an incline (4 miles) while catching up on my favorite shows or movies – it’s actually the only time I allow myself to watch TV! Doing this genuinely makes me look forward to my 1-hour of fasted cardio.
Remember – all you have to do is be moving; what you’re doing doesn’t really matter, as long as it feels good to you! Make sure you stay hydrated and stop immediately if you feel weak or dizzy.
How do I fast intermittently?
There’s actually more than one way to fast intermittently, so don’t be discouraged if you find that you think it doesn’t work for you. Give any of these a shot:
- 16:8: Fast for 16 hours, consume calories for 8 hours.
A common schedule for people following this pattern is to place the 8-hour eating window at the later part of their day. For example, someone who goes to bed at 10PM and wakes up at 6AM will fast from 10PM until 1PM. This is where your fasted morning workout fits in.
Some people just can’t live without breakfast – that’s fine! Those people will make their eating window from 8AM-4PM, and exercise in a fasted state in the afternoon.
- 5:2, 24 hour: Skipping 2 meals, 2 days per week.
For example, you will eat your last meal at 8PM, and not eat until 8PM the next day, for 2 out of every 7 days. It is not recommended to exercise on days like these, even at low intensity.
- Alternate Day Fasting: consume 25-50% of your standard calorie intake, every other day.
- Warrior Diet – named after the way, well, warriors would go about their day – not eat at all, then feast within a 4-hour window in the evening prior to sleep.
Keep in mind:
- Fasting does not excuse bingeing: Just because your skipping a meal does not mean you should go all out with junk food. If anything, your body is in its most pure state after a fast, so you want to nourish it with the best you can give it.
- Exercising while intermittent fasting is not for everyone. If you’ve tried it for 1-2 weeks and you’re not happy, don’t put yourself through it! Exercise and diet are lifestyle changes that are mean to make you feel good, not punish you.
- If you know you have blood sugar issues or health issues that could be problematic, consult a physical prior to attempting to exercise in a fasted state.
Previously a dancer, Ashley has been practicing yoga for over 15 years and teaching for 5.
She balances an executive-level “corporate” position during the day with healthy, mindful wellness practices in her free time to stay grounded; she lives on celery juice and cold brew, and can’t live without her dark chocolate!