Extreme events reveal an alimentary limit on sustained maximal human energy expenditure, 2019, Thurber et al

Open access, https://advances.sciencemag.org/content/5/6/eaaw0341

https://www.bbc.co.uk/news/health-48527798

 

I'm not sure this make sense, according to information I have seen during the middle ages the number of calories expended by a serf was in the region of 5,500 a day, if they were available.

4000 seems awfully low given many people eat considerably more than that when training.

Or are they defining ordinary people as people who don't need more than 4000 kcal a day? In which case the result is unsurprising.

 

I find this curious as I know some ultramarathoners who can run 500+km in a week... They'd be burning on average about 4000-5000 Cal(kcal) per day on top of their BMR.

The implication is this cannot be maintained for 20 weeks...

 

I think this is interesting, but I struggled to follow the logic in places (mainly due to the extra reading I would have to do).

Looks like it’s observational at this stage rather than any detailed proposal of mechanism. They suggest liver I think, but I wonder about other things more mundane, like down regulation of secretions during exercise (e.g. stomach acid). I’m still a bit confused about the pregnancy bit though?