# Several questions regarding heart rate **URL:** \ **Category:** 60+\ **Created:** [23 January 2022 15:49 UTC](https://forum.intervals.icu/t/several-questions-regarding-heart-rate/6371 "2022-01-23T15:49:32Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Todd\_Bowen](https://forum.intervals.icu/user_avatar/forum.intervals.icu/todd_bowen/32/4032_2.png) [@Todd\_Bowen](https://forum.intervals.icu/u/Todd_Bowen)\ **Post date:** [23 January 2022 15:49 UTC](https://forum.intervals.icu/t/several-questions-regarding-heart-rate/6371/1 "2022-01-23T15:49:32Z")
``` In the Northern Hemisphere it is winter. I have noticed that when doing hard outdoor efforts for the same power my heart rate does not come up. The outdoor temperatures that I'm specifically talking about are 20-30F/-6--1C. I can put out really high power and never get my heart rate in to Z5 and struggle to get it into Z4. I would be curious what the physiology is. I suspect vasoconstriction of extremities is shunting blood to the heart. In turn this gives the heart more to work with, i.e., more stroke volume. Next thought is, if the muscles are getting less blood (vasoconstriction) are we hurting recovery, is there a training benefit perhaps? For me the central question becomes if we hold the above to be true how do I pace for a 100k gravel race in FREEZING cold weather? Normally I would pace to a HR of 150-155. But now for this race it is hard to know how to pace. I'm guessing your answers will be RPE will have to be the way to pace. What are members of this group experiences with HR and very cold weather cycling? ``` Bonus second question regarding heart rate and heart rate drift. If you ride a “perfect” Z2 ride with temperatures constant, fueling and nutrition are dialed and you observe drift occurring at two hours. Does this tell you anything about how many hours of Z2 you should be doing to get the most benefit. My guess is in the example above that at two hours you are starting to get benefits. And how much longer should I go to keep making gains, 3,5,7. Keep in mind my A race this year will be 12 hours on the bike. Should I keep progressing to this length of ride? ---
**Author:** ![Steve\_Tucker](https://forum.intervals.icu/user_avatar/forum.intervals.icu/steve_tucker/32/74441_2.png) [@Steve\_Tucker](https://forum.intervals.icu/u/Steve_Tucker)\ **Post date:** [23 January 2022 16:07 UTC](https://forum.intervals.icu/t/several-questions-regarding-heart-rate/6371/2 "2022-01-23T16:07:36Z")
Regarding your second question, if you ride more Z2 then your decoupling should improve as well, if it were me and bearing in mind your 12 hour race, (you don’t say when it is) I would start building up my Z2 hours to 3, 5, 7 . I would also start to do some tempo work as this is probably where you will spend much of your time for your A event. Later maybe some sweetspot and sweetspot bursts but keep the endurance going as well. ---
**Author:** ![Michael\_Webber](https://forum.intervals.icu/user_avatar/forum.intervals.icu/michael_webber/32/38823_2.png) [@Michael\_Webber](https://forum.intervals.icu/u/Michael_Webber)\ **Post date:** [23 January 2022 23:20 UTC](https://forum.intervals.icu/t/several-questions-regarding-heart-rate/6371/3 "2022-01-23T23:20:00Z")
Good thinking, @Steve_Tucker. I’d add this, @Todd_Bowen: later in your build-up, make some of the long Z2 rides back to back – a couple of consecutive days of 3+ hrs, then 5+ hours and finally 7+ hours. I wouldn’t do longer than that in training. ---
**Author:** ![Steve\_Tucker](https://forum.intervals.icu/user_avatar/forum.intervals.icu/steve_tucker/32/74441_2.png) [@Steve\_Tucker](https://forum.intervals.icu/u/Steve_Tucker)\ **Post date:** [24 January 2022 09:35 UTC](https://forum.intervals.icu/t/several-questions-regarding-heart-rate/6371/4 "2022-01-24T09:35:26Z")
Yes, I agree with @Michael_Webber about the back to back long rides. I do that myself at the weekend and a typical week for me at the moment is Mon: Day off Tue: Intervals ( Tempo or sweetspot later with bursts) Wed: Mid to long Z2 ride Thursday: Recovery ride or short Z2 Friday; Intervals (Tempo or sweetspot) Sat: Long ride Sun: Even longer ride ---
**Author:** ![Michael\_Webber](https://forum.intervals.icu/user_avatar/forum.intervals.icu/michael_webber/32/38823_2.png) [@Michael\_Webber](https://forum.intervals.icu/u/Michael_Webber)\ **Post date:** [24 January 2022 12:45 UTC](https://forum.intervals.icu/t/several-questions-regarding-heart-rate/6371/5 "2022-01-24T12:45:34Z")
This is Todd’s first question: In the Northern Hemisphere it is winter. I have noticed that when doing hard outdoor efforts for the same power my heart rate does not come up. The outdoor temperatures that I’m specifically talking about are 20-30F/-6–1C. I can put out really high power and never get my heart rate in to Z5 and struggle to get it into Z4. I would be curious what the physiology is. I suspect vasoconstriction of extremities is shunting blood to the heart. In turn this gives the heart more to work with, i.e., more stroke volume. Next thought is, if the muscles are getting less blood (vasoconstriction) are we hurting recovery, is there a training benefit perhaps? For me the central question becomes if we hold the above to be true how do I pace for a 100k gravel race in FREEZING cold weather? Normally I would pace to a HR of 150-155. But now for this race it is hard to know how to pace. I’m guessing your answers will be RPE will have to be the way to pace. What are members of this group experiences with HR and very cold weather cycling? I’m sorry, Todd, but I can’t answer this question. I am not a physiologist and I do not live in a place where the temperatures get into those ranges. I do know that temperature [amongst other things: eg, hydration, coffee] affect the Power: HR ratio. ---
**Author:** ![Todd\_Bowen](https://forum.intervals.icu/user_avatar/forum.intervals.icu/todd_bowen/32/4032_2.png) [@Todd\_Bowen](https://forum.intervals.icu/u/Todd_Bowen)\ **Post date:** [24 January 2022 13:14 UTC](https://forum.intervals.icu/t/several-questions-regarding-heart-rate/6371/6 "2022-01-24T13:14:56Z")
The cold weather HR not rising is something I have never seen addressed anywhere. My event is 9 months away. I’m currently doing a build program and sneaking in a long Z2 whenever the ice goes away. And fasted, short, 1-1.5 H Z2 on the trainer whenever I think it won’t effect the next days performance/recovery. Thanks for your input, @Steve_Tucker, @Michael_Webber, ---
**Author:** ![Michael\_Webber](https://forum.intervals.icu/user_avatar/forum.intervals.icu/michael_webber/32/38823_2.png) [@Michael\_Webber](https://forum.intervals.icu/u/Michael_Webber)\ **Post date:** [27 January 2022 21:45 UTC](https://forum.intervals.icu/t/several-questions-regarding-heart-rate/6371/7 "2022-01-27T21:45:44Z")
@Todd_Bowen Have you seen this? [Why Can't I Go As Fast When It's Cold? - Fast Talk Laboratories](https://www.fasttalklabs.com/physiology/why-cant-i-go-as-fast-when-its-cold/). It’s behind a login wall, but free. If you don’t want to join fasttalklabs, then: . when you’re a cold, you have less oxygen delivery, because your muscles are vasoconstricted, the blood vessels aren’t open as much, and ultimately, there is less oxygen available to the muscles, and you simply cannot work as hard . if your body temperature is lower than desired, lower than optimal, your muscles are going to respond by generating heat through shivering and that is extra oxygen that is being taken away from your ability to actually push the pedals . in terms of a dynamic movement, such as with pedaling a bike, it is our skin temperature that can really drive our instantaneous force production. So you don’t necessarily want really cold skin, you want to cooler skin in terms of maintaining heat flow out from your body, but you don’t necessarily want to have it ice cold in terms of your skin temperature . when our muscles are cold, we simply have to do more work to generate the same force. Warm up + lots of clothes. I don’t know what this means for HR. But we have to think about our lungs being cold? ---
**Author:** ![Todd\_Bowen](https://forum.intervals.icu/user_avatar/forum.intervals.icu/todd_bowen/32/4032_2.png) [@Todd\_Bowen](https://forum.intervals.icu/u/Todd_Bowen)\ **Post date:** [27 January 2022 22:09 UTC](https://forum.intervals.icu/t/several-questions-regarding-heart-rate/6371/8 "2022-01-27T22:09:00Z")
@Michael_Webber that is fascinating. It makes sense. The mechanism is totally different than I suspected. To add to this I have seen that legs should be covered up to temperatures of 65F/18.3C. So from what you found I would be better off over dressing my legs for this cold race that I have coming up. With regard to the lungs, I use a buff so that I can breathe warmer air. The buff is the one good thing that I learned during Covid while playing on my bike. ---
**Author:** ![Steve\_Tucker](https://forum.intervals.icu/user_avatar/forum.intervals.icu/steve_tucker/32/74441_2.png) [@Steve\_Tucker](https://forum.intervals.icu/u/Steve_Tucker)\ **Post date:** [27 January 2022 22:21 UTC](https://forum.intervals.icu/t/several-questions-regarding-heart-rate/6371/9 "2022-01-27T22:21:43Z")
What about using hot embrocation does that actually increase the blood flow? I have always done that in cold weather when racing in shorts, unless very cold of course when I would wear leg warmers. ---
**Author:** ![Todd\_Bowen](https://forum.intervals.icu/user_avatar/forum.intervals.icu/todd_bowen/32/4032_2.png) [@Todd\_Bowen](https://forum.intervals.icu/u/Todd_Bowen)\ **Post date:** [6 February 2022 14:46 UTC](https://forum.intervals.icu/t/several-questions-regarding-heart-rate/6371/10 "2022-02-06T14:46:25Z")
Was just reviewing your words before my race today. From my business in Anesthesia, I know that shivering increases oxygen utilization by %400 percent. I will be on the bike for 4-5 hours today in temperatures of 32-40F. I am really hoping that I put on the right pair tights for the job. The other comment that I have is that our legs have less temperature sensory neurons than any other part of our bodies. That is why you can wear shorts in winter in not necessarily feel like your legs are cold. If we cycle with shorts in cooler weather we are actually doing muscle damage. Just some thoughts. I hope your day is great. ---
**Author:** ![Michael\_Webber](https://forum.intervals.icu/user_avatar/forum.intervals.icu/michael_webber/32/38823_2.png) [@Michael\_Webber](https://forum.intervals.icu/u/Michael_Webber)\ **Post date:** [7 February 2022 07:43 UTC](https://forum.intervals.icu/t/several-questions-regarding-heart-rate/6371/11 "2022-02-07T07:43:24Z")
I hope that your race went well, @Todd_Bowen. And that your legs were cool, but not cold. My day was ‘Meh’ – some damage to the inside of my right quad, just above and to the left of my patella. Easy for a couple of days = catch up on neglected housework. Therefore ‘Meh’. ---
**Author:** ![Todd\_Bowen](https://forum.intervals.icu/user_avatar/forum.intervals.icu/todd_bowen/32/4032_2.png) [@Todd\_Bowen](https://forum.intervals.icu/u/Todd_Bowen)\ **Post date:** [7 February 2022 15:15 UTC](https://forum.intervals.icu/t/several-questions-regarding-heart-rate/6371/12 "2022-02-07T15:15:35Z")
Sorry to hear about your injury. It is hard to take time off from training good luck on the healing(and the chores-Meh). Only 3 old guys racing, but I was faster than the other two :). ---
**Author:** ![Michael\_Webber](https://forum.intervals.icu/user_avatar/forum.intervals.icu/michael_webber/32/38823_2.png) [@Michael\_Webber](https://forum.intervals.icu/u/Michael_Webber)\ **Post date:** [8 February 2022 01:23 UTC](https://forum.intervals.icu/t/several-questions-regarding-heart-rate/6371/13 "2022-02-08T01:23:56Z")
Yay! The 60+ group has a victory. The season’s first? ---
**Author:** ![Todd\_Bowen](https://forum.intervals.icu/user_avatar/forum.intervals.icu/todd_bowen/32/4032_2.png) [@Todd\_Bowen](https://forum.intervals.icu/u/Todd_Bowen)\ **Post date:** [8 February 2022 17:30 UTC](https://forum.intervals.icu/t/several-questions-regarding-heart-rate/6371/14 "2022-02-08T17:30:03Z")
I guess it would be. Next on agenda, how to recover without loosing fitness. Yikes, such a fun game that we play on bikes. Hope your quad is feeling better.