Why does my heart rate spike in a workout?

If you find your heart rate raising inexplicably in the middle of a workout without an associated increase in exertion level, there are a few possible explanations. First you need to see if this occurs on the exact same stretch of road. The receiver on the heart rate monitor often picks up extraneous electrical signals from sources such as power lines. If this is happening at approximately the same time in your workout, I would suspect this is coming from the same source. Another possibility is that the battery in your chest strap and in the receiver of your heart rate monitor is getting low and is giving you faulty readings. Replace the battery to rule out this possibility. A third alternative explanation is cardiac drift, a slow rise in heart rate which can be caused by dehydration or other factors. A small increase in heart rates (3-5 beats) can be accounted for due to this phenomenon on account of dehydration. However if you are drinking and your spike is higher than 3-5 beats, I would recommend contacting a medical professional for further inquiry.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.