> no brand can be accurate on energy expenditure because it depends on a lot more things than what the watch can monitor. I was going to quip that I can probab

> no brand can be accurate on energy expenditure because it depends on a lot more things than what the watch can monitor. I was going to quip that I can probably look at a person and state their energy expenditure with 70 % accuracy (whatever that means -- I'm going to assume coefficient of determination.) Just someone's weight alone ought to have nearly a 70 % r² with energy expenditure. (A quick internet search suggests 71 % though I have not bothered verifying their methodology.[1]) Of course, they could mean 70 % across days for the same person, which is significantly more impressive as it takes out the strongest signals, but it's not at all clear what they actually mean and that's sort of my point. Edit: I read the article closer now and when they say 70 % they actually mean a Pearson r of 0.7, i.e. a coefficient of determination of 50 %. Reporting r as a percentage seems confused at best, or possibly dishonest. [1]: https://www.researchgate.net/figure/The-relation-between-body-weight-and-total-energy-expenditure-or-intake-as-linear_fig2_7178754 https://www.researchgate.net/figure/The-relation-between-bod...