Upfront

Dessert? Skip it

Counting on how many calories your fitness device says you burned today to justify dessert? Pass. 

New research shows that seven devices designed to track calories burned are “way off the mark,” says Euan Ashley, DPhil, senior author of a paper published May 24 in the Journal of Personalized Medicine.

The worst-performing device was off by more than 50 percent; the best by an average of 27 percent.

But the news isn’t all bad.

Heart rate tracking “performed far better than we expected,” with an error rate on six devices of less than 5 percent, says Ashley, professor of cardiovascular medicine, of genetics and of biomedical data science at Stanford.

His team used medical equipment to monitor 60 volunteers who wore fitness trackers — an Apple Watch, Basis Peak, Fitbit Surge, Microsoft Band, Mio Alpha 2, PulseOn and a Samsung Gear S2 — as they ran or walked on treadmills, or pedaled stationary bikes.

Additional Reading

Plus

The dealer is in

When Anna Lembke began working as a psychiatrist in the late 1990s, she told clinic intake coordinators not to send her any patients with addiction to drugs or alcohol. She soon discovered she had no one left to treat.

Two minds

The cognitive differences between men and women