Calculating Max Heart Rate


On @mcneese.chad’s POL thread yesterday we touched on keeping in zones based on % of max heart rate; this got me thinking…

The highest HR I’ve ever recorded is 184bpm - this was recorded while running (1 mile intervals). I’ve never come close to this HR while cycling. In fact the highest HR I’ve ever recorded while cycling is 174bpm, while doing a 10 mile TT (was fully spent!). My understanding of this is that running uses more muscles, so requires a higher HR.

Based on this all my HR zones are set based on my max HR being 184bpm (max running HR).
My calculated aerobic threshold (that I try not to exceed on easy days) is 142 bpm (77% of max HR).

If my HR zones were calculated based on the max HR I’d ever recorded on a bike, the zones would look pretty different. I’d need to ride quite a bit easier than I currently do to keep in the lower zones.

This got me thinking about cyclists setting zones based on max HR. If a cyclist has only tested their max HR based on cycling, is that actually even close to their true max HR?


You should be using your maximum applicable to that particular sport. But a 10 bpm difference between running and cycling sounds a little high.

You are unlikely to reach your maxHR during a 10 mile TT - the amount of time you can sustain maxHR is not really compatible with the pacing required for that event. You are more likely to hit your maxHR on a maximum effort 2-5 minute hill climb.

Before adjusting your target HR zones, I’d suggest testing your cycling maxHR more precisely.


Agreed, a 10min TT isn’t the kind of effor that’s going to produce a max HR anyway. I didn’t even get close to mine with my ramp test.

I see max HR with big efforts at the end of a lot of sustained work; ie: that final sprint to the top of the climb when you’ve been digging deep up it. Stop sign sprint at the end of a fast group ride. I’m sure someone smarter than me can chime in, but I assume it has to do with stressing aerobic and anaerobic systems to their maximum.


I’ve seen a few people state this before, but it’s never made sense to me. Heart rate measurement is assessing the cardiovascular stress, irrelevant of the activity. Your heart doesn’t know if you’re cycling/running/swimming, it simply responds to whatever training you happen to be doing. Surely if I’m cycling at 142bpm, the cardiovascular stress is the same as running at 142bpm, so why would you have different training zones for different activities?

From what I’ve read it seems pretty common that max HR from running is higher than when cycling, but yes, 10bpm may be pretty high. With cycling I possibly fail at a muscular level before being able to fully aerobically stress myself. It’d be interesting to hear what any other triathletes have found.

I live in a hilly part of the world (Yorkshire), so have done plenty of hill climbs! :sweat:, but still haven’t exceeded 174bpm on the bike.


My method for max HR is: do the Trainer Road ramp test, then (especially if your pain cave is nice and cool) add 2 or 3 for good luck.


Agreed. I’ve also found that a 1, 2, or 3 minute all out effort will also get close if you pace it correctly. The 1 minute is the easiest for me to reach max, assuming I’ve warmed up. But I’m only hitting that at the very end for only about 5 seconds.


I think that is close for me too. 183 bpm peak in recent Ramp. Likely have a 185-186 bpm peak based on outside rides and a super hard effort 2 years ago.