Threshold HR... or not?

[Sittingduck]

So, I was pretty confident that my threshold HR was 169-170. I have seen this kind of figure a few times on very high effort rides / races (mostly a year or two ago). Very similar number for both a 10 mile TT, 45 mins crit and a 1 hr+ road race. However, on Saturday I managed to somehow average 174, for an hour. The way I see it, there can be two reasons for this:

1. What I thought was my threshold, actually wasn't and I had a little left in reserve during the previous efforts
2. Threshold HR has actually increased - but as I am now a cpl of years closer to my pension, I find this prospect surprising. Would have thought a gradual decrease over the years was much more likely.

Realise that HR is affected by a number of things and not a fantastic measure but at the moment I can't afford a power meter. Although, have rented one, in the past.

Any thoughts? By the way, I'm kind of anticipating the usual 'forget about it and just ride' feedback but am curious, none-the-less!

 

[Citius]

If the effort level was the same (ie actual RPE, not HR-based), then maybe your heart was just working harder than usual on that day. Were you going any faster? That's what matters...

 

[Sittingduck]

If the effort level was the same (ie actual RPE, not HR-based), then maybe your heart was just working harder than usual on that day. Where you going any faster? That's what matters...

Definitely working at full effort on Sat but it was a windy day and the circuit was very exposed. Speed wise it was high for the first 3 laps then dropped 2mph for the rest of the hour (about 8 more laps). Being shelled out of the back of the bunch on a really windy day probably had a lot to do with it, just surprised that a difference of 5bpm was sustainable, over an hour.

 

[Citius]

But - you sustain the effort level, not the HR. You need to see the two as separate. If the effort level was the same (sounds like it was) then it just means your heart was beating faster on that day.

 

[Tin Pot]

What is your definition of threshold and how are you calculating it?

 

[Sittingduck]

What I am able to sustain at full effort without totally going into the red and blowing up. Calculating it by reviewing the HR achieved on time trials and races.

Although I think I may have calculated it a little conservatively, according to other 'stuff' I have read.

 

[Citius]

Your threshold will be governed by the ability of your body to metabolize lactate - not by your heart rate. The two tend to track together reasonably well most of the time, but there is no direct correlation. You can't really use your HR as a 'rev counter' - not reliably, anyway.

 

[Rob3rt]

Like you anticipated, I am going to suggest you ignore it and carry on UNLESS it becomes repeatable. In which case, adjust training zones and carry on.

 

[Sittingduck]

Aye... have a club TT tonight, assuming roadworks are gone on the A24. First TT in a cpl of years so will be interesting to see the results.

Edit: It's cancelled