# Heart Rate Monitor Question

**URL:** <https://boards.straightdope.com/t/heart-rate-monitor-question/388201>\
**Category:** Factual Questions\
**Created:** [January 16, 2007, 4:15pm UTC](https://boards.straightdope.com/t/heart-rate-monitor-question/388201 "2007-01-16T16:15:30Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\
**Post date:** [January 16, 2007, 4:15pm UTC](https://boards.straightdope.com/t/heart-rate-monitor-question/388201/1 "2007-01-16T16:15:30Z")

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I was at the gym last night and I was using my usual treadmill, which has the two metalallic handholds that somehow measure your heart rate. So how exactly does this work? I know that if I remove one hand it doesn’t work so I figure it forms some kind of electric circuit. Can someone explain it in simple terms?