Intermittent fasting/OMAD and marathon training

[thomasbaerten]

I've been doing intermittent fasting for a while now and the results are very good. (Been slacking of since the summer holidays but back at it now!) Also thinking of trying One Meal A Day.

Now, for my usual workouts (beginner Pete plan) I'm not worried since I often take crossfit classes fasted.
My fasted workouts are often better than when I've had a meal.

But now I'm planning to train for a marathon row. So I will be going for longer workouts at once a week, slowly increasing per week. Does anyone have experience with fasting and longer workouts?

Any advise or thoughts are welcome!

[Dangerscouse]

I have never done a long workout fully fasted, but I have done up to 30k on a banana and a strong coffee. After that you almost certainly will need carbs, and it may bite in the 25-30k or even 30-35k range as we are all different.

[Yankeerunner]

Back in my prime I tried fasting and gave up on it quickly. It left me far too weak. At the time I was running some fairly good marathon races.

Instead of total fasting I devised a regimen that I could live with both physically and mentally. I was feeling a bit heavy and sluggish, about 8 pounds over what seemed ideal for me at the time, and I was racing weekly at distances from 9 to 18 miles leading up to marathon day. After a Sunday race I'd cut down to 2000 calories/day through Wednesday or Thursday. Then go up to 2500 for a day or two, and eat normally (3000-4000 calories) on Friday and Saturday to load up for the next Sunday race. That way I only had to be miserable and have hunger pains for a few days, which I could tolerate, and indulge before racing which put me in a good mood. In six weeks I lost the 8 pounds (145 to 137), and raced a marathon PB.

While it might not work for everyone, it might provide some ideas for developing a plan of your own.

[thomasbaerten]

Thanks for the feedback! I'll use the longer training sessions to experiment with some different approaches.
It's just when I row after a big meal. I feel my blood sugar dropping really fast.
So maybe no big meals before I row, but more smaller snacks during rowing?

[Yankeerunner]

I'd never run or row after a big meal unless my life depended on it, and then my life would be in serious jeopardy.

Putting at least several hours between a big meal and a big effort is best. Most of my marathons were morning or early afternoon events, and my last big meal would be a high-carb spaghetti feast the night before. Sometimes it would be 17 hours between the meal and the race with only minor sipping of coffee or water, or at most an English muffin with jam several hours before. The body has a remarkable ability to store glycogen in the blood, liver and muscles until it is needed.

My last marathon, this past Feburary was an evening event though, starting at 6:30 PM and I had my spaghetti about 5 hours ahead of time and that worked out fine too.

[thomasbaerten]

Did my first OMAD yesterday, followed by a 12k training (55 minutes).
Last meal on Monday: 7PM
Training Tuesday: 6PM
Meal Tuesday: 7.30 PM

So far, so good. No drops in energy at all.

I'll give an update on how things are going regularly for people who are thinking on doing the same thing.

54:47.4 12,000m 2:16.9 136 768 23
9:21.3 2,000m 2:20.3 127 735 23
9:11.0 4,000m 2:17.7 134 760 23
9:15.0 6,000m 2:18.7 131 750 23
9:06.7 8,000m 2:16.6 137 771 24
9:15.7 10,000m 2:18.9 131 749 24
8:37.6 12,000m 2:09.4 162 855 27

[thomasbaerten]

Little update

Wednesday: fasted till noon (we had a teambuilding event with lunch) - weight training in the evening
Thursday: rowing at 5PM - fasted till 7PM. No problem
Friday: rowing at 5PM - fasted till 7PM. No problem
Saterday: Crossfit at 10AM - Fasted till noon. Really hungry an hour after workout was finished.
Sunday: Fasted till noon. 2 hour walk in the afternoon.

I'm going to keep the swithing things up between omad and fasting till noon depending on my agenda.
This week I will row a 14K. First time going over 60 minutes on the rower.

[thomasbaerten]

For anyone who is looking for info/tips in the future I will keep posting my experiences and findings every couple of weeks.

I've been doing IF/OMAD for 5-6 weeks now.
Very happy with my fasted training sessions. No drops in energy at all. I try do do them straight after work, around 4 - 4.30PM
Had to do some sessions after dinners and they were a bit slower. I felt sluggish and had spikes and drops in my energy levels. So I'm doing as much as fasted sessions as possible. Sometimes life gets in the way

For sessions more than 70-80 minutes I break my fast during rowing. Around 60 minutes in.
I have been calculating the amount of calories I need take in to keep going after this point.
Every 15 minutes I eat a bit of banana bread and/or drink some isotone drink.
So far, so good. But I will need some more sessions to find out if this will work once I pass the 2-hour-mark.
I'll come back to this in a couple of weeks.

[Erik A]

interesting and ive been toying with the idea of intermitant fasting for a bit. ended up have about a 25hr fast last week that was a bit unintentional. had lunch on friday that was pretty heavy (pasta) and then didnt eat again until after lunch the saturday. i also did my usual friday evening session at the gym with no downturn and to be honest i had no issues with hunger or any apparent side effects and if anything felt quite a bit better than normal. less bloated etc. and on the plus side i appear to have dropped about 1kg. may add in a day of fasting once a week and see how that goes

[thomasbaerten]

So far so good. I really like switching between the 16-8 and 20-4 pattern depending on the schedule.
Last monday I was forced to do a 10K an hour after my only meal of the day, which was terrible. Blood sugar spiked and dropped dramatically and had to stop midway. Did the same session two days later after a 21-hour fast. No problem.

The weight hasn't come of for now, but that was mainly due to the holidays. Basically a 3-week-party.
Back at it since january 2nd and I feel great. Wrote down my weight and belly circumference and will do this again at the beginning of each month.

I track my fasts now with an app called 'Zero'. It gives you an average fasting time for the last 7 days. The goal is to keep this number above 16.