Heart rate 25-30 bpm higher after flu recovery

Hey Everyone,

I got a bad flu (not COVID-19) and had to take three-to-four weeks mostly off from cycling, running, etc. While easing back into workouts I noticed that my average heart rate for workouts is about 25-30 bpm higher than for the same workout pre-flu (e.g., 128 vs 155 for Pettit).

For reference, I did get blood work and other tests done since it aligned with an annual physical, and nothing appeared unusual. Additionally, I cross-checked the heart rate data from my Polar strap against my Garmin watch and both pretty closely mirror one another so it isn’t a device issue.

Lastly, although I’ve noticed slightly elevated heart rates after being sick or taking time off in the past, it’s never been to this extent and on a prolonged basis. It also doesn’t feel like I’m working as hard as the heart rate suggests. Has anyone else experienced something like this before?

Thank you!

Yes, after 3-4 weeks off my fitness declines by a lot. My on ramp to training is doing 1-2 weeks of easy aerobic workouts by HR, to get the cardio engine warmed up. Then start training again.

Some people don’t lose fitness as fast, and bounce back quicker.

Pretty normal. You have lost fitness and probably a lot of blood volume build during training so you heart has to beat more often to pump the blood.

Thanks for the feedback. It seemed like a greater deviation than usual for fitness loss, but perhaps I’m just getting old…:unamused:.

Thanks for the feedback. It seemed like more of a fitness loss than usual, but it’s a longer than usual break. I’ll keep at the low intensity endurance work a monitor performance.

Just looked because I was riding by HR for 3-4 weeks…. In September my second week of restarting cycling (not training), riding at zone2 HR had power at 120W for an hour. A month later it was back to 180W. Pretty big jump. I remember being happy when it went above 150W at same HR.

Scrolling back to Christmas 2017/2018 when I got a bad flu that almost killed me (a year and a bit later I found out why :open_mouth: ). In Dec 2017 my Ave HR for cycling was around 125bpm and post the flu in Jan 2018 it was circa 145-150 bpm for cycling. A fluctuation of that much is definitely not normal for me however but you’ve had blood works and other tests done so I worry about anything untoward and I hope you are back to normal shortly.

Thanks for sharing your experience with building back up. I’ll keep going with the lower intensity endurance rides and cross training for the next 3-4 weeks and see how heart rate trends.

Thanks for sharing your experience and I’m glad your recovery went well. It seems like, unfortunately, I’ll have to suck it up and build back over the next 3-4 weeks before jumping into more intense training.

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Same happened to me recently after a surgery. The preceeding weeks were:

  • 1 week off after an A race
  • 4 weeks of Z2 only
  • Surgery then 2 weeks off

Resting heart rate jumped 25bpm along with a similar increase for Z2 rides. Dropped FTP from 240 to 200 to get the HR about the same for long Z2 & Z3 rides. 2 weeks into structured training again and things are now starting to point in the right direction and I expect to regain the old fitness pretty quickly (say 2-3 months). Resting HR is still 60 (was 42) so that has a long way to go.

I appreciate your sharing your recovery timeline. It sounds pretty similar with my resting heart rate coming back a little faster (back down to 55, but still have a little way to go). Hope you get back to full fitness soon!