HRM warning in dry winter months

heybales

The warning comes for those using the HRM for hitting HR zone goals for focused cardio training (endurance/performance), or if you are using it for counting calories.

Even if you have all the stats the best they can be for the best estimate of calorie burn you can get from the HRM, this issue will impact it.

Chest straps have issues getting accurate reading of HR if there is abundance of static electricity. It's trying to read the changing state of your heart's electrical charge, and that is messed up. Usually you get spikes very high.

This usually has nothing to do with weak batteries, because if batteries got that weak, your HRM receiver would have stopped receiving the signal already.

So what causes static electricity problems?

Of course dry air, easier in the winter usually.
Workout clothes designed for wicking sweat away are usually all or mostly polyester, and when it rubs against your chest or poly shorts, static.
Fan flapping those clothes in the air. Normally effects bikers at anytime because of that effect.

So the problem - your HR usually reads higher than it really is. If bad it will just keep going progressively higher making you wonder how you are working harder. Sometimes it's just enough to elevate it by 10-15 bpm and you'd never know because you feel like you are moving just as normal, and you are.

The problem with that is your calorie count is totally inflated now, and if trying to stay in a certain zone for training, you really were working easier than you wanted.

To test, you can usually just press your shirt up against the HR strap to stop the flapping and rubbing, and it'll start dropping within 5 seconds even though you are keeping your workout going at same pace.

Solutions some have found useful.
Dryer sheets rubbed on HR strap and shirt, easy for gym bag.
Anti-static clothes spray on shirt and between poly fabrics.
Tucking sides of shirt into strap to make the front tight, and bottom of shirt into shorts to stop flapping there.
Misting water on inside of shirt and between poly layers.

Might as well include a nice link.
http://www.dcrainmaker.com/2010/04/troubleshooting-your-heart-rate.html

Some HR straps are worse than others.

http://www.polarusa.com/us-en/support/Abnormal_Heart_Rate_Readings_During_Exercise

https://support.garmin.com/support/searchSupport/case.faces?caseId={7b3ce1b0-6d24-11dc-6782-000000000000}