If you’re out riding fat bikes in snow, cross-country skiing or just running in negative temps, you may be wondering: does pulse rate slow down during cold weather? Short answer—potentially, yes. Longer answer—potentially, but this is all good information!
Heart rate is a great tool and one we encourage all the athletes we coach to use (yes, even if they have power!). Using your heart rate, feeling and RPE will give you three great ways to guide your workout and progress your training.
READ MORE: Should you use HR, Power or RPE?
One of the criticism that heart rate gets is that it is variable. There are environment (temperature, altitude) and individual (cadence, fitness, fatigue) factors that can influence heart rate. Now, you can also argue that even when heart rate is variable, it’s very important information! Fatigued and pushing through an interval workout? If your power numbers and heart rate don’t match up the way they normally do, that doesn’t mean you should ignore what your heart is telling you—it’s a good indicator that you may need an extra rest day.
But what does that mean for cold weather riding and how your heart rate may change based on temperature? In basic terms, when there is less need to cool your body, your heart doesn’t need to work as hard to get blood to the skin (for cooling) AND to your legs for pedaling! This might seem like a downside, but this reflection of the strain on your body (or heart) and can be valuable if pacing compared to using power.
Practically, when it’s hot outside, you may ride lower in your endurance zone (e.g. zone 2) power while keeping your heart rate within that endurance heart rate zones.
Your Heart Rate will Likely Be Lower in the Cold
For cold weather, the reverse may be true (though it depends a lot on your personal physiology, in addition to how many layers you’re wearing!). When it’s cold out, you may find it hard to get your heart rate up into the endurance zone, so you may find you ride in zone 1 heart rate while power is in zone 2 power. A caution is to avoid pushing much higher power (and feeling – RPE) when experiencing these low heart rates.
So, generally, if it is cold out and you notice a lower heart rate, this is completely normal.
However, it’s worth double checking that you aren’t pedaling slowly due to the cold. This may be the case for fat bikers who are riding without power on their fat bikes and solely relying on RPE and heart rate—you may just not be used to riding on snow yet, or you may be slowing down a bit in the absence of measured power. Try doing spinups and faster cadences generally to see if you’re able to bump up your heart rate.
There are also more long term reasons your heart rate may be depressed. Long term fatigue and overtraining also would be reasons to see a depressed heart rate so taking a day (or three, or seven!) isn’t a bad idea, especially if you’re also noticing a lower heart rate when on the indoor trainer, or if you’re feeling otherwise fatigued outside of riding.
Lastly, you may also want to troubleshoot your heart rate strap—sometimes, that can be the problem! (Want to learn more about heart rate strap maintenance? Check out this video here.)
Want to learn more? Check out this episode of the Consummate Athlete Podcast where we talk about cold weather heart rate.
