Intermittent fasting and veganism while rowing?

[Erik A]

For info I didn't lose any measurable weight during my 11.5hr row, it was during the training that the fat went in a measurable sense. THe PM5 suggested i had burned 6107Cal

I weighed myself immediately before/after the 11.5hr session, and taking into account the food/fluid intake, had lost no weight at all (taking into account these are domestic scales so there may have been some variance).

I think the point we are both making is that balance is key to being healthy and able to exercise as one wishes.

Whether the fasting has a detrimental effect is imho partly about ensuring that calorific intake on average allows the bodies energy stores to be replenished (accepting your comments about protein).

thats really interesting. I did a marathon walk late last year. took me 7 hrs 20 and i dropped like 6kg and i was drinking a lot. probably too much as i had to find a toilet at the 12km mark. my health app said i burned 2700cal. i didnt do it on an empty stomach but had minimal food prior and only a few bars etc during. i drank water at every checkpoint and had 3l on my back which i drank plus after the half way was drinking the energy drink at each checkpoint as well as the water.

[Erik A]

Having watched the film "Game Changers", it was encouraging to see that the world's strongest man is 100% vegan. He probably eats a lot though and doesn't fast.

I would take that with a grain of salt as that particular person has never been the worlds strongest man. he may have competed but im pretty sure he has never won it and if you look at him now he has gone back to eating meat. that doco was a pure advertisment for the producers to try and get people to buy their vegan products.
it was interesting but not very convincing

[GlennUk]

thats really interesting. I did a marathon walk late last year. took me 7 hrs 20 and i dropped like 6kg and i was drinking a lot. probably too much as i had to find a toilet at the 12km mark. my health app said i burned 2700cal. i didnt do it on an empty stomach but had minimal food prior and only a few bars etc during. i drank water at every checkpoint and had 3l on my back which i drank plus after the half way was drinking the energy drink at each checkpoint as well as the water.

Out of curiosity what was your body mass at the time?

Your caloric values is worth about 300g of fat, assuming that the energy was all derived from burning fat, which i would doubt.

From memory a 2% loss in body weight due to sweating puts you in the a risk area with regards to your health (at the time, not sure if it has any lasting effects).

Even accounting for your visit to the toilet that's a huge loss, assuming your not 300kgs?.

[robhely]

Having watched the film "Game Changers", it was encouraging to see that the world's strongest man is 100% vegan. He probably eats a lot though and doesn't fast.

I would take that with a grain of salt as that particular person has never been the worlds strongest man. he may have competed but im pretty sure he has never won it and if you look at him now he has gone back to eating meat. that doco was a pure advertisment for the producers to try and get people to buy their vegan products.
it was interesting but not very convincing

I didn't know that he'd gone back to eating meat. I think a lot of top level athletes have tried all sorts of diets, such as plant based, to try and get the edge. I wasn't totally convinced by everything in the doco, but it was slightly better than the atrocious doco that came out afterwards attempting to debunk it. The meat industry vs vegan product producers using good old fashioned screen-based propaganda.

[robhely]

What I'm concerned about is high intensity exercise on an empty stomach when I row in the mornings. I'm wondering if this is a good idea. How important is it to ingest calories before and after exercise?

Here is one set of studies on this explained. The speaker is an elite endurance cyclist. There is a lot of simulatiry between cycling training and rowing training for rowing events 2K and longer. There are 10 studies linked in the description if you want to DIY research. I didn't cross check, but in the past the speaker accurately presents the studies.

the TLDR version is
1. you are fine with fasted workouts, and should keep doing them.
2. you will see benefits in longer pieces from fasted workouts by training for a more efficient muscle economy.
3. there might be benefit in eating before intense workouts for people who are doing long enough events that they need to eat during the event (marathon for example or endurance cycling).

Thanks, that's a really good resource for research on fasted training. My takeaways are:

1. fasted workouts are fine (and even beneficial) on low intensity training days.
2. fasted workouts are not ideal for high intensity training days or races/PB attempts.
3. definitely some benefits overall for endurance.

[robhely]

There is lots of conflicting information on social media. This is not to say that it is all equally valid. You shouldn't take me as an authority because I'm still learning, but I have watched and read a lot. Here are my impressions.

Everything credible I've read confirms that vegetarian is the healthiest option, in all respects.

Intermittent fasting and time-restricted eating are current fads with very little outcome evidence to support them. It does seem to be a good idea to avoid snacking between your last and first meals of the next day. It does seem to be a good idea to spread your protein across at least 3 feeding intervals at least 3 hours apart, and not skimp on breakfast protein. But you don't need to obsess over it. Just eat your beans/lentils/nuts. Timing doesn't seem to matter as much as one might think, but within an hour of resistance exercise seems good.

If you do cardo while fasting, most of your energy will come from glycogen, and you may crave carbs to replace that. The slower you go, the higher proportion of fat. But your homeostasis will arrange that it doesn't really matter much.

If you're not trying to lose weight, I don't see the motivation to exercise while fasting. Even if you are, be careful of the extent to which the weight you lose is glycogen and muscle rather than fat.

At your age, one of your paramount concerns should be maintaining your muscle strength and muscle mass.

I've also concluded that there is much credible evidence in support of a mainly plant based diet.

For me intermittent fasting has made a noticeable difference in overall energy levels, recovery and immunity to colds and flues. I used to 'bonk' massively sometimes when doing long rides or workouts, but now my blood sugar levels seem to be better regulated and I can even do a lot of exercise on an empty stomach if I have to. I agree that the timing isn't that important, the main thing is to give the body more time to deal with other processes rather than just constantly digesting food. This can be as simple as just cutting out that evening snacking and not having dinner too late or breakfast too early. I've read a lot of credible research on this.

I have no real motivation to exercise while fasting, it's more just a timing thing as sometimes I like to row in the mornings before work, which is always on an empty stomach and followed by a few more hours before breakfast/lunch. I'm going to do some experiments with timed pieces in the morning vs afternoons where I'm well fed.

Definitely agree that it's super important to maintain strength and muscle mass, if this means changing my routine to only work out in a well fed state I'm prepared to do that.

[Elizabeth]

What I'm concerned about is high intensity exercise on an empty stomach when I row in the mornings. I'm wondering if this is a good idea. How important is it to ingest calories before and after exercise?

Here is one set of studies on this explained. The speaker is an elite endurance cyclist. There is a lot of simulatiry between cycling training and rowing training for rowing events 2K and longer. There are 10 studies linked in the description if you want to DIY research. I didn't cross check, but in the past the speaker accurately presents the studies.

the TLDR version is
1. you are fine with fasted workouts, and should keep doing them.
2. you will see benefits in longer pieces from fasted workouts by training for a more efficient muscle economy.
3. there might be benefit in eating before intense workouts for people who are doing long enough events that they need to eat during the event (marathon for example or endurance cycling).

Thanks, that's a really good resource for research on fasted training. My takeaways are:

1. fasted workouts are fine (and even beneficial) on low intensity training days.
2. fasted workouts are not ideal for high intensity training days or races/PB attempts.
3. definitely some benefits overall for endurance.

Anecdotally, I've set a number of PBs and a couple of WRs (albeit on slides) while fasted. However, my recovery seriously suffers if I don't eat pretty soon afterwards.

I'm not currently training fasted for a number of reasons, none of which would apply to you.

[Erik A]

thats really interesting. I did a marathon walk late last year. took me 7 hrs 20 and i dropped like 6kg and i was drinking a lot. probably too much as i had to find a toilet at the 12km mark. my health app said i burned 2700cal. i didnt do it on an empty stomach but had minimal food prior and only a few bars etc during. i drank water at every checkpoint and had 3l on my back which i drank plus after the half way was drinking the energy drink at each checkpoint as well as the water.

Out of curiosity what was your body mass at the time?

Your caloric values is worth about 300g of fat, assuming that the energy was all derived from burning fat, which i would doubt.

From memory a 2% loss in body weight due to sweating puts you in the a risk area with regards to your health (at the time, not sure if it has any lasting effects).

Even accounting for your visit to the toilet that's a huge loss, assuming your not 300kgs?.

just saw this and thought i should respond. my BMI was 36 at the time so in the double extra fat category. i am a sweat beast at the best of times. i sweat watching a program about the desert. i walk in the middle of winter in temps less than 5deg c and sweat with just a T shirt and shorts on. never really affects me that much although at the end of that marathon i was pretty beat up mainly as i undertrained. i drop about a kg when doing my normal nights walk of between 6.5 and 8km so not that different from my perspective.

[GlennUk]

just saw this and thought i should respond. my BMI was 36 at the time so in the double extra fat category. i am a sweat beast at the best of times. i sweat watching a program about the desert. i walk in the middle of winter in temps less than 5deg c and sweat with just a T shirt and shorts on. never really affects me that much although at the end of that marathon i was pretty beat up mainly as i undertrained. i drop about a kg when doing my normal nights walk of between 6.5 and 8km so not that different from my perspective.

I guess this just highlights how we are all different, a 6kg loss and you were 'drinking as lot' is quite extraordinary, if asked i would say i sweat a lot, but nowhere near such volumes.

Have you always been this way? I noticed a change in how my body responded to thermal stress when as a new firefighter i had to wear clothing which prevented heat loss through sweating when working. Something that has never really gone away, but not in the volumes that affect you.

[iain]

I thought that 2% loss was when it had a significant effect on body strength, I have lost 5% body weight a few times without long term effects. On Sunday I lost 2kg in weight during a 50km row despite drinking over 2l of drink and I started at just under 75kg (although over hydrated and with some food and water in my stomach at the start). IIRC glycogen is associated with approx. 3 times its mass of water, so if you use 400g of glycogen you will lose 1.6kg in weight without effecting water available to the body. THis is a major reason why some people who mistakenly drink to replace lost weight can suffer from over hydration.

[Erik A]

just saw this and thought i should respond. my BMI was 36 at the time so in the double extra fat category. i am a sweat beast at the best of times. i sweat watching a program about the desert. i walk in the middle of winter in temps less than 5deg c and sweat with just a T shirt and shorts on. never really affects me that much although at the end of that marathon i was pretty beat up mainly as i undertrained. i drop about a kg when doing my normal nights walk of between 6.5 and 8km so not that different from my perspective.

I guess this just highlights how we are all different, a 6kg loss and you were 'drinking as lot' is quite extraordinary, if asked i would say i sweat a lot, but nowhere near such volumes.

Have you always been this way? I noticed a change in how my body responded to thermal stress when as a new firefighter i had to wear clothing which prevented heat loss through sweating when working. Something that has never really gone away, but not in the volumes that affect you.

yeah ive always been a heavy sweater. one of the side effects is chaffing which is a pain. i also am very cold tolerant which is possibly a side effect of the heavy sweating or the sweating is because im very cold tolerant. it annoys my wife no end as she wants the fire going and im sitting there with a singlet and shorts on.