As well as tracking movement, FitBits can also monitor our pulse and heartrate, showing us dips and spikes throughout the day.
And when Israeli FitBit owner Koby Sato got dumped last week, he noticed some pretty interesting stats for his heart rate at the end of the day.
Koby's heart rate normally rests at around 72 beats per minute (bpm), but when he got an unexpected call from his boyfriend to end their relationship, that heart rate jumped right up to 88 bpm.
— Koby (@iamkoby) January 19, 2016
His heart rate remained high for the rest of the day, once even spiking to 118 bpm – we're guessing that was the standard "OH GOD I'M GOING TO BE ALONE FOREVER" moment we've all experienced at one point or another.
Speaking about the results, Koby said he thought it was a cool way to prove that heart break really does affect how we feel.
"Everyone understands heartbreak, right? Everyone’s felt it. When you have this, it’s interesting – you have something to show."
We'd like to see Koby's ex-boyfriend's heart rate when he realises his break-up's just gone viral…