Here’s a weird one for you. 90 minute Z2 ride today. My Max HR is around 185bpm but I don’t think I’ve seen above 181bpm in the past year. VO2 max I go for >170bpm. Threshold is around 165bpm. Normally, Z2 is 120s up to low 130s. Hopped on the bike and within about 30 minutes my HR was over 140bpm. By 45 minutes it was over 150bpm, and maxed at 160bpm. Which is crazy for Z2. I didn’t feel overly tired or weird. Legs felt ok. But I was just watching it tick higher and higher at the same power. Then, all of a sudden, it dropped back into the high 120s/low 130s. No changes. Fan on the entire ride. When it was at 160bpm, I double checked with my Apple Watch and did a manual calculation holding my pulse. It was 160bpm.
So one, I don’t know why a fairly easy Z2 ride would push my HR up to 160bpm when it’s normally around 130. But also, why did it seemingly fix itself for the last 30 minutes of the ride. If it was aerobic decoupling, it shouldn’t have gotten better. I’m stumped.
Edit: Should have used the ECG feature to check my rhythm even if it’s not perfect. Didn’t feel lightheaded, dizzy, or faint at any point throughout the ride.
Edit: The only thing I could possibly think of is dehydration coming into the workout, and then as I’m drinking fluids during the ride I rehydrate.
What is the source for the heart rate data? Asking because it appears quite “spikey”. E.g. ±20 bpm swings in under a minute while at steady power. If I saw something like that in my data, I would suspect a measurement error before I worried about a physiological problem. Disclaimer: Not a doctor, just a guy who has had one or two wonky HR recordings when HRM chest strap was dry or my watch was being weird.
The ~45 minute peak in HR during ~LT1 rides is a phenomenon we’ve discussed on this forum before. I don’t know why it’s true, but it is true for me & many other riders.
Maybe? The target was 60% FTP so not exactly the hardest. Usually for these just spin the legs a little and then set erg so I can zone out. I’ve never done warmups for rides like this in the past.
Interesting. I guess it’s throwing me off because one, I’ve never experienced it in the decade or so I’ve been training, and two, my HR was getting close to Threshold levels while riding at 60% FTP.
The spike is definitely weird. especially since you’re using a chest strap. Have you been sick at all very recently? I had a virus of some sort recently. Felt awful for a week. Then over the next 3 weeks I felt better but it had some stop and starts with workouts as things would feel off. Did some zone 2 rides that felt fine but HR was way high. But in my case it just stayed high. There was no spike.
Not sure that helps but with any unusual readings that don’t match my RPE I just chalk it up as an anomaly and make a mental note to keep an eye on it for upcoming workouts.
Unless you notice some fatigue or other systems I’d assume it’s probably past. I just mentioned it because myself and a few friends had viruses that we felt bad for a few days then had lingering fatigue over 2-3 more weeks where you sort of felt okay but then you’d start to exercise and realize you were not. In your case, it doesn’t sound like you have those symptoms
