Hacker News Reader

Comment by jackconsidine | Hacker News Reader

After reading Behave, I hold Sapolsky in high regard. Even if he provides weak evidence for the claim, the grandmaster in the article loses 15 pounds- or a whopping 11% of his body weight- on average during a 10 day tournament which is striking.

View on HN

Still not burning 6000 calories.

> In our study, we found calorie expenditure during chess competition (156.8 ± 65 kcal) and during running exercise (282.9 ± 82.7 kcal) were significantly different from each other, simply due to the overload effect of skeletal muscles during exercise.

https://journals.lsu.lt/baltic-journal-of-sport-health/artic...

This study found that energy expenditure when playing chess was ~2.3x higher than when resting.

And these are just amateur players. Maybe it's not 6000 calories but it is a significant increase over the base rate.

This can simply happen because of a change in eating and drinking habits during a 10 day tournament.

This take seems overly skeptical to me. Regardless of truth of the 6,000 calorie claim, that kind of weight loss is extreme in such a short amount of time.

To the contrary, you're being underly skeptical. This is a huge claim to base of a sample size of one guy at one event.

To state the obvious that I hope doesn't need to be said to this audience: a sample size of one tells us exactly nothing. What's saying this one guy one time didn't have a nasty stomach bug?

A crazy claim like this requires some kind of study not just one guy's story.

That's a 5200 calorie deficit per day.

So no, not really. At least not without significant dehydration.

I'm more skeptical of the weight loss claim itself.

Well, up to 8lbs could be water weight. If you have excess calories, your body will retain water. If you disrupt that excess you'll rapidly lose 8 to 10 lbs. Weight loss often has great results in week one, then levels off, so a portion of this could be attributed to eating less and increased stress during a tournament.

8lbs if you're already severely overweight or loaded on carbs, maybe. These guys don't exactly look like they are doing either of that. To put it in a different perspective, that amount of weight loss beats out strict waterfasting at the same weight. You can't get much more strict than straight-up dehydrating (because we all know dehydrating yourself prior to a mental exercise is a great idea) or doing rigorous exercise outside of that.

And no, chess is not rigorous exercise. If it was, the room would be too hot for them to wear suits and tuxedos. Those burned cals have to go somewhere. For the unconvinced, try jogging or lifting 2000 calories worth in a suit at room temperature or slightly above without taking it off.

I bet food poisoning would do it. Because, like you said, they aren't burning those calories - 6,000 calories in a single chess game would leave them in a giant pool of sweat.

Dehydration isn't about water, its about electrolytes.

And 4 lbs could be series of bowel movements

I can "lose" 10+lbs in 24-48 hours just by fasting, more if dehydrated.

Of course, defecation must not be confused with burning body mass.

not unless there is such a change, and it has to be significant to loose such weight. what does happen though is an increase in mental strain as the tournament progresses.

Doesn't stress come into play here too?

I think people are conflating "weight" with "fat". It's very believable to me that they lost 15lbs in 10 days, some fat, probably mostly water.

I know my weight can fluctuate as much as 10lbs in a day depending on how much I've been sweating, eating, drinking, exercising over the course of the day.

It could be attributed to stress, perspiration and change in water intake behaviour. In other words water weight.

4kg of water, 0.5kg of glycogen, 2kg of debris in bowels. The rest is what they really lost.

Reply on news.ycombinator.com