cmh

I gave blood on Thursday, Friday was a rest day, then did 3x20 sweet spot intervals today on my rollers. I was able to hold the same speed as usual (so presumably the same power) but my heart rate was 10 -15 bpm higher (more or less right at my normal LT heart rate). I can imagine the other way around, sitting in a race at LT power with your heart rate 15 bpm lower after boosting your hematocrit. That would feel nice. I'm assuming my red blood cell count is low and that is the reason for the high heart rate. I think it takes at least a week to build up to a pre-donation hematocrit (I'm sure someone here knows how long it takes).

Strangely my percieved exertion was right where it usually is for SS intervals, but I imagine if I had tried to go anaerobic I would have seen a big drop in output. My heart rate just didn't have that much further it could have gone up.

ElJamoquio

I think new blood cells take two weeks or more to mature, and they aren't all made at once, so I'd suspect three weeks or more to reach previous levels.

ridethecliche

Did you drink coffee before riding? That could have had the same effects.

El Diablo Rojo

There are so many variables when it comes to HR that you can't say it was because of you giving blood. Temps, amount of sleep and diet (like cafffine) can all effect HR.

Grumpy McTrumpy

I'm going with Occam's Razor on this one. I think it's due to low crit. Simplest answer tends to be the right one. When I have caffeine it affects my resting HR, but not so much my FTP HR.

Coyote2

Well, you're technically correct that it takes at least a week, because it actually takes at least three weeks.

There's a reason why The Red Cross makes you wait 56 days between donations. Though that is probably the long end (for safety's sake). I read up on this once and believe I found that the best case scenario is about three weeks to get back to the original red blood cell count.

gsteinb

Would I have been faster without the nose bleed?

cmh

There are a lot of variables with regard to HR, but in all of the times this winter I have done 20 min. 'sweet spot' intervals on my trainer, my HR hasn't been nearly this high. I'd say my HR varies by +/-5bpm or so from workout to workout given about the same percieved exertion. For this ride my hr was a solid 10 bpm, and at times 15bpm higher than normal.

cmh

Did you lose about a pint of blood?

procrit

Ahh, item number 1436 at excelsports.com, under miscellaneous doping products... 1pt frozen blood, choose your own blood type, $43.99 + shipping.

kensuf

They must be back-ordered. All I could find was cera listed under accessories.