The FastDay Forum

Hi Kimbo

I wondered if you embarked on any exercise on fast days, like you was I am unsure if its the right thing to do or not, some fast days I feel so tired its hard for me to do the mile or so walk I have to do to get to work - I usually run regularly and zumba once or twice a week so its not like I never exercise at all.

I took a long break from exercising for a while, several weeks where I didn't run or do strength exercises at all, barely even went for my customary walks. I felt very tired, and had no motivation.

Taking a break from exercise had no effect on my weight-loss, and I think it was the right thing to do for me, because this way of life is not meant to be a source of stress.

After my break, I am back to exercising and loving it. I feel happier and more energetic, and my condition was not set back more than what I could recoup in a few days. I prefer to exercise on fast days, my body has been filled up with energy from eating the day before, and the way it lifts my mood and makes me feel good in my body is perfect to counteract the sluggishness or grumpiness fasting can cause.

Today I didn't have any coffee before my run, and I could tell I was running slower than normal, but who cares?

I think I definitely need to try some exercise on fast days just to dispel the myth from my own mind, once I know I can do it I can bring my exercise days back up to where they used to be

I schedule my fasts for Mondays and Thursdays because those are my Strength Training Class days and also my days for afternoon volunteer shifts. It's important for me to be out and about, busy, on fast days as opposed to being home thinking about food. I feel a little weak before breakfast the day after a fast, though, so I don't do my early morning workout on those days.

So, as others have suggested, experiment a little and see what works for you.

Welcome and best of luck.

I'm usually at Crossfit (strength & conditioning) for a couple of hours on fast days. Not been this week and finding it harder! Both hungry and not distracted...

Kimbo - I started exercising and dieting last February in preparation for a large holiday, too. I found this WOE in March and switched to this, so I had already been developing endurance and an exercise habit.

I'm a registered nurse, so I like the "nerdy" stuff in the "nerd section". It makes sense to me that fasting forces your body to 'burn up' your glycogen stores (sugar/easy energy). Somewhere around 12-16 hours after your last meal, they say that your 'easy' energy storage is gone and your body has to start burning fat. Whoo hoo!!! That's theoretically why this WOE helps people lose fat at higher percentages as opposed to other 'diets'. The nerdy stuff goes on to say that if you exercise on fast days, you are bringing your body into that 'fat burning zone' sooner and for a longer period because you're burning those calories/that glycogen up faster when you add in your exercise.

The end result, according to all that nerdy stuff, is your body becomes more efficient at burning fat.

There's all sorts of research and so on to support this - I read all that nerdy stuff when I'm looking for extra motivation.

At any rate, I was 'in a hurry' to loose, too, and managed to lose 30 pounds before my trip - we left on May 29th. I ate as close to zero carbs on my fast days as I could possibly manage and a healthy measure of protein. My fast days always look something like a huge, huge, huge veggie salad that still weighs in at only about 70-100 calories - romaine lettuce, raw spinach, peppers, onions, sometimes radishes, broccoli, cucumbers, whatever I have. You can eat a LOT of vegs for a tiny bit of calories and I personally only like them raw. I indulge in a rich, high-fat/low-carb dressing of some sort for about another 100 calories, put a lid on the whole thing and shake the heck out of it so the dressing covers it all - and spend my last 300 calories on a hefty hunk of protein - chicken, pork, beef.

Because I was 'in a hurry', I still watched my eating/calories on my non-fast days, too. Limit sweets, try to stay under my TDEE-300 daily calorie goal, etc.

We went to Disney World for 2 whole weeks and ate on their 'disney dining plan'. I did 16:8 there very easily almost every day, and thanks to that and all the walking, even though I ate like a pig the entire time, I did not gain back any of the weight I lost!

Now, I'm home and 5:2 again and not quite so strict on my non-fast days. It seems my weight loss will dip down to .5 pound/week or so at my current WOE, but I am very satisfied with that, as it is very long-term sustainable for me. I can always get a little 'stricter' with myself on my non-fast days if I want to speed it up, and might do that after the kids are back in school, but right now it's summer and I want to enjoy the resultant fun/outings/eatings that occur.

Long ramble, hope that helps, good luck and have a lovely holiday!!

Completely forgot! I somehow neglected to mention the exercise point - I did exercise and still do, nearly every day. I mostly fast-walk and try to do it an hour a day, usually a half hour sometime mid-day during my lunch break at work and another half hour at home in the evening, sometimes an hour then. I'm trying to build up to running as that burns more calories per minute spent, and can now run 5 minutes/walk 2 for about 2 miles. I do this even on my fast days - ESPECIALLY on my fast days - and it does not bother me in the least. I have my best runs/least fatigue on my fast days.

When I walk/run, I carry wrist weights. They started out 1 pound and are now 3 pounds. I mostly just pump my arms while I move, but I spend a little time doing overhead presses and so on to tone and strengthen arm muscles as well as the legs/general calorie burn. I like it! And I wore tank-tops on my vacation without being embarrassed of flabby arms!

I run a few times a week - varying distances but I'm meant to be building up to a 10k. Haven't managed much over 3K lately though (various reasons!). Anyway, today was my third fast day and the first time I tried exercising on a fast day. Because of the heat I waited until the evening - about 8:30pm, so I had used my day's calories. The run itself was fine, but I found that my blood sugar plummeted when I got back and I found myself feeling quite lightheaded and faint, so I got a banana down myself sharpish. This obviously tipped my calories beyond 500, which is definitely preferable to fainting, but has this happened to anyone else? Do you have any tips/advice for exercising on fast days?

I run a few times a week - varying distances but I'm meant to be building up to a 10k. Haven't managed much over 3K lately though (various reasons!). Anyway, today was my third fast day and the first time I tried exercising on a fast day. Because of the heat I waited until the evening - about 8:30pm, so I had used my day's calories. The run itself was fine, but I found that my blood sugar plummeted when I got back and I found myself feeling quite lightheaded and faint, so I got a banana down myself sharpish. This obviously tipped my calories beyond 500, which is definitely preferable to fainting, but has this happened to anyone else? Do you have any tips/advice for exercising on fast days?

Were you done exercising for the day? If so, you could have just rested and drink some fluids and you would have found the faintness and dizziness to go away fairly quickly. You certainly would have depleted your body's glucose stores during your exercise, but with fluid and rest it would have rebuilt those using fat.

As your body gets used to fasting, it will become more and more efficient at burning fat, which is what we want, but takes awhile to get there. I thank you did exactly the right thing for your body at that time. eventually you will find that you don't need to replenish the burned energy.

Good for you for making such progreas toward your 10k! I'm working my way toward a 5k and still have a ways to go.

Hi everyone, I'm on a fast day today. Not gonna eat anything til dinner time, I have 2 more hours at work and then was going to go to the gym. Is a workout a good idea after just green tea and water?

I am now on week17 of 5/2 and have always exercised. On my very first fast day I walked 6miles during the day and went to Zumba in the evening with no Ill effect (and I am 67) You won't know what you can do till you try it.

So my day so far...

Went to a physio session with a friend and ended up on a mini-trampoline bouncing on one leg, some ring rows and dumbells. Then had a quick technique session for olympic weight lifting, specifically snatch. Then warmed up more with a row, movement prep and then a squats session. Followed by a met con consisting of more squats, overhead presses and burpees. Finished off with a max effort sit-up with a weight.

I am 41, still obese, female, if I can do this on a cup of coffee... You can do anything once you are adapted to burning fat, just get there gently.

Hi everyone, I'm on a fast day today. Not gonna eat anything til dinner time, I have 2 more hours at work and then was going to go to the gym. Is a workout a good idea after just green tea and water?

You'll have to find what works for you. As you see by the responses you've already gotten, most people can exercise on a fast day without any problems. you might get a little more tired or have to back down your intensity level on fast days at first. As your body becomes more efficient at burning fat for energy, exercise on fast days will get easier.

I went for it in the end, it was fine thanks for your replies