For the challenge, each viewer wore an Apple Watch. Data collected was based on the Health app's heart-rate tracker. It's not perfect science, but it gets the idea across.

How fast does your heart beat? It’s a tough question to answer, because our heart rate changes all the time depending on what we’re doing and how our body is behaving. However, ...

According to Mashable, the Heart Rate Challenge originally involved 20 individuals, but only data on five people — all of whom were pushing over 125 BPM barely 20 minutes into the film — made ...