Exercise and Intermittent Fasting

llr841

Hi There,
I have been doing intermittent fasting for the past four weeks (16:8) and have almost lost those last few kgs. I finish my last meal for the day around 5.30-6pm and have my first meal for the day around 10am.

I would like to exercise first thing in the morning but because I am still in fast mode I don’t have the stamina to do a good workout or run.

Has anyone else found this a problem?
Any suggestions?

joyanna2016

I always exercise during my fasting window. It works fine for me as long as I'm hydrated.

RockingWithLJ

I have worked out with and without eating 60-90 before a workout and if I had to choose one I would definitely eat beforehand. I found I had more energy and motivation to push through. It's only a problem if you become lighted too often.

lgfrie

Been working out before my noon-7pm eating window, for over a year, never had a problem. Hydration is key, though. If you're not feeling energetic, you might need to eat something before you work out. I mean, it won't harm your weight loss to shift a hundred calories to the morning so you can have some food in your system for a run. Gotta make the eating schedule work for you, rather than fighting it.

llr841

Yes, I’m probably not hydrated enough now that you’ve mentioned it. Maybe a banana may be an option if hydration isn’t enough..

natasor1

I do intermittent fasting for many years. Normally, it's 20-4 hrs. For one year in addition to intermittent fasting I do fasting for 2-3 days, and I do exercise on empty stomach anyway. If you feel lightheaded or week, it means your body is not adjusted yet for fat burning. Let it get used to fasting and keep you energized with your own fat storage. Your body will learn how to switch quickly from glucose to fat burning and your energy will be almost unlimited. The other advantage will be that you won't feel hungry for many hours. Try to stretch your fasting window from 16-8, to 18-6, 20-4, 24 (one meal a day). Before going on fast fast eat only protein and fat, exclude carbs.

yirara

I could not because my blood pressure and energy levels are too low before I eat anything. I'd probably faint if I tried working out. Everyone is different. That it works for some people is great. But don't assume it does for everyone.

Avidkeo

I am a runner, and found I couldn't do any more than 5k fasted. Any run longer than that I had to have a banana or something before or I just didn't have the energy to get through.

Some do fine, some don't. Do what works for you.

sijomial

Has anyone else found this a problem?
- Yes

Any suggestions?
- Start out gently (shorter duration, lower intensity).
- Build up slowly over a period of weeks.

Might work for you or might not but how you feel right now may well not be a good indicator of how fasted exercise works out once you adapt to it. I felt awful at first and had to break a couple of fasts to recover even after very moderate exercise but eventually intense exercise up to two hours just felt totally normal.

janejellyroll

I am usually done eating by 8-9 PM (so a bit later than you) and I always exercise first thing in the morning, before breakfast, unless I'm doing more than 10 miles or so. Anything more than 10 miles and I find I have to eat. I will also let my hunger be my guide. If I wake up on a random day and feel just super hungry, I will go ahead and eat something light, even if it's a shorter run.

SnifterPug

I much prefer exercising fasted. I don't typically start eating until at least 2pm, though, so my last meal is closer to my workout than yours is. If I know I will have a heavy PT session doing weights I might dunk 50cals worth of protein powder in a coffee just beforehand.

Diatonic12

Don't confuse disordered eating under the guise of IF or any other name. Extreme strategies beget more extremes.

Thoughts always precede behaviors. Destructive thought patterns lead to poor eating and lifestyle choices. They'll only dig you into a much deeper hole with food.

heybales

I've many many nights finally getting to eat at 10:30 pm until midnight.
The next day I'll do a 1.5 hr ride @ 6:30 pm without issue. Or 2+ hr ride on Sat 4 pm. All fasted of course.
My job is very sedentary so not exactly using liver glucose.
You can train body to get used to it if just more convenient.

But, and this is big - I'm eating enough calories even in a diet.
If I was to go for extreme deficit, there would be issues with not getting enough carbs replenished.
So of course I'm eating more on those workout nights allowing the workout the next day.

OP - how much deficit you taking?

Because unless you were active through the evening using up lots of carbs for higher intensity movements, a proper eating level should make morning not so bad. YMMV of course.