Heart rate training in evening

andyeb

I normally train using heart rate as my key indication of intensity. I like it because it's an objective measure of how hard I'm working - I find RPE far to subjective.

Normally I do sessions on the turbo first thing in the morning - get up early, have a medium sized breakfast, let it go down for an hour, then get on the bike. This works well.

However sometimes I go to train in the evening, or to do the local 10 mile TT and I have to work much, much harder to get the same heart rate response. This often puts an end to a planned 2x20m tempo workout within minutes - I work up to the desired heart rate planned for the session, but I can tell I'm working much harder than I expected and generally die 2-3 mins into the 20 minute interval.

Any ideas why this might be? To start with I thought it was a case of not leaving long enough between having dinner and exercising, but this evening I left it 2.5 hours (rather than the usual hour) and still had the same problem.

thanks,

Andrew

imposter2.0

HR is not - as you put it - an objective measure of how hard you are working. It is simply a measure of how fast your heart is beating. Although there is obviously some correlation, as you have seen, your HR for one session could be very different from your HR the next time you do that same session. Assuming you already know what a tempo effort feels like (without referring to your HRM), just work on RPE - which if you think about it, is not actually 'subjective' at all. What you should be targeting is the effort level, not the HR number, because the two are not the same thing - and only one actually tells you how hard your body is working.

Barbarossa

What happens to your HR if you do your morning session before breakfast?

andyeb

Barbarossa wrote:

What happens to your HR if you do your morning session before breakfast?

It's pretty much the same, although I do have trouble sustaining tempo work if I haven't fuelled for the session.

woolwich

Andrew,

I think the differences in HR you experience are neither the result of the time of day nor when you last ate. Rather the environment that you are training in, i.e. outside and not on the turbo.

I realise that some coaches/books/on-line guides state that you can work out your training zones on the trainer and they will relate well on the road, this is probably true when training with power but I have found them quite hit and miss with heart rate. Somebody on here that I sold a bike to recently stated that they should all training zones should be calculated in the context they are to be used, so similar bike, environment etc. I think this is probably good advice.

I get similar results to yourself with a HR monitor and have stuffed up 10 mile time trials as a result of being over reliant on the figures and not trusting RPE. My best guess is that it is something to do with body cooling. Even on hot days your heart is not tasked with cooling the body as much as on a trainer due to your whole body moving through air. I barely sweat on the road but despite a big fan and opening all the windows the stuff runs off me at home.

SBezza

I would avoid trying to get up to a target HR as fast as possible and then hold it there. If you know how hard a session should feel you have to go on that, then as you are into a interval and you HR has risen use that. HR response is so variable that it means nothing really. If doing an interval on the turbo set it up the same every time and use rear wheel speed as a measure of intensity, if you then do a similar session on the road, remember how it feels on the turbo and try and replicate it. HR could be quite different on the road compared to the turbo. You should never die 2-3 mins into a tempo interval, this is a effort you should be able to keep up for 2 hours, if you are dying, then you are obviously going off far far too hard.

To be honest I find RPE a bit vague, but it is a better intensity indicator than HR in all honesty, though using both together can be useful.