elevated heart rates and heat

You'll never die honorably, on your mountain bike, if you keep listening to these ninnies go on about rest and hydration.

 

I get the same issues with my HR monitor sometimes. Using Spectra electrode gel makes it go away. It's cheap. It's less than $6 for a 250mg tube on Amazon, and one tube should last you for years.

 

+1. Tube of this lasts forever and it helps pick up the beat from the first second. No waiting to get sweaty or licking the sensors. And try a new battery in the strap.

As for heat, i normally ride in the cool morning or night. When i ride in the heat of the sun, i have experienced about a 10bpm increase over my normal rates. Certainly never over 200 though.

 

Which heart rate strap are you using? If you're using the newer Garmin soft strap, instead of replacing the battery just pick it up and chuck it in a dumpster, or give it away to someone you dislike. It is a hunk of crap regardless of battery levels. You will receive constant spurious readings, extremely high readings, extremely low readings, and sometimes no readings at all. I had one for 2 years and had constant problems until it finally died completely. I thought it was just how HR monitors were, but it turns out that model is just a pile. The older hard strap is far better made, functions flawlessly every time, and has been known to last 10+ years. Make sure you wet the electrodes for better performance before you ride. My base HR definitely increases with heat, and also lack of sleep or hydration. One thing to keep in mind is that it is very difficult to reduce your heart rate in high heat once you pass a certain threshold, make sure you monitor your heart rate closely to keep it in a sustainable zone on hot days and dial back if it gets too high.