The Apple Watch might not be as popular as the iPhone — but some devoted wearers have good reason to ‘heart’ the smart timepiece.

So says company Chief Operating Officer Jeff Williams, who talked about the health benefits some Apple Watch users have experienced in an interview on Jan. 4 with the radio show Conversation on Health Care.

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“Quite honestly we’ve been surprised and very inspired,” Williams said on the program. “So many people have written to us saying it’s helped them lose weight, it’s helped them be more active, they were pre-diabetic and have changed course.”

Read More: 5 Things to Consider Before Buying an Apple Watch

“And even, we’ve gotten a ton of emails where people are saying the watch actually saved their life,” he said. “In a way we didn’t anticipate we’ve gotten so many emails where people or their cardiologist have written us and said this person detected something on their watch and came in and they had a life-threatening situation and, if we had not intervened, they probably would have died.”

In the past, fitness-band wearers have flooded online forums with complaints that their devices actually cause them to gain weight as they perhaps overestimate the health effects of all the steps they racked up that day.

The only real sensor of a somewhat medical nature on the Apple Watch is the heart-rate monitor, as Williams noted in his interview. And not everyone's so confident that smarter tech translates into healthier lives. The makers of Fitbit are facing a lawsuit that alleges that the Charge HR and Surge models of the popular fitness device don't accurately report heart rates during exercise.

The American Heart Association recommends that anyone who believes they are experiencing a heart attack, stroke, or any form of cardiac distress should call 9-1-1 and seek medical attention immediately.

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