I did 2 FTP tests on the bike recently. The weather was cool (nice spring weather) so temp probably wasn’t a factor. I averaged the same heart rate for both tests. Is that my threshold heart rate on the bike?
I think that the official protocol to find LT is to test the blood while on an ergometer (or treadmill).
It’s often estimated as 80% of max HR.
I think that you can also experimentally find it by using perceived exertion. It’s often the HR you are settled at during the middle of a medium distance effort (medium is relative…say 30 minute effort).
Just taking the average HR over an entire effort doesn’t seem as likely to be the LT as you will take a while to get up to LT upon starting. Did you find your HR hovering somewhere? How long were your intervals?
It was 2 x 20 min intervals (2 min rest between). I did 2 tests and then looked at each interval seperately (relatively flat course). My avg heart rate for each interval was 170. Just curious if there was anything I could glean from that. I’m pretty sure that my heart rate zones are way off. I don’t train with heart rate at all so it doesn’t matter from that stand point. But I do like to review the data post ride and track how much time I’m spending in each zone just for shits and giggles.
Well, your average HR was the same which is encouraging from a consistency point.
Was your actual performance ie. distance or avg speed/power also consistent?
If so, then I’d say that you paced yourself very well and probably never surpassed your LT. So the max HR you saw during these might be your LT…what was your max? (I would expect your LT slightly higher than the average).
Pretty close. My wattage for the first interval on each test was slightly higher than the second interval but only about 5-7 watts. I could have paced a little better but they were close.
The short answer is yes, that will be a perfectly fine estimate of your threshold heart reate. It’s going to within +/- 5 bpm IMHO.
Well, if your average HR was the same, but your performance was falling off on the second one then it’s entirely possible that you did find your LT and your perceived effort self-selected you there.
What was your actual HR curve like? Can you show us the HR chart over time for both efforts (preferrably overlayed).
Either way, it sounds like 170 is darn close and that may be all you need to know because your actual LT will vary from day to day. It’s lower during your warmup and it’s higher after a good warm-up. It’s higher when you’re fresh…much lower if/when overtrained…it’s a moving target.
I don’t have my file handy to post but I will get it tonight. I just plugged in 170 for my HR zone and calculated via Coggan and those zones look much more in line with what I see when I’m training. My old threshold was set at 159 and my heart rate zones always seemed way too low. These seem pretty accurate.
Yeah, I can guarantee you that your actual threshold is not BELOW the average of 170 that you found…although if you’ve been gaining seriously in fitness over time, that number could have been your LT at one point.
The 159 was from a test I did last year with the coach I was using. I was way out of shape and just getting into cycling. So you think my LT is probably higher than the 170?
Yes I do, but not necessarily much higher.
If I saw the actual HR charts I could ‘guess’ at a number that would be a little more accurate than the average that you found.
The reason I think it’s higher is that I don’t think you could have spent 20 minutes above your threshold (that’s a swag, but the idea is that if you crossed your LT say in the middle…at the 10 minute mark…then you couldn’t have held above your LT for the remaining 10 minutes…at least not while holding everything together so well for the 2nd one).
Your LT is probably just a touch above the 170. If you were at LT for 20min. it would have been really tough to replicate the effort on 2min. rest.
Your LT is probably just a touch above the 170. If you were at LT for 20min. it would have been really tough to replicate the effort on 2min. rest.
Why?
It’s just another 20-min at or near threshold, which (presuming you mean TT level threshold and not Lactate Threshold which one could sustain for several hours) you’d expect to be able to sustain for about an hour if you wanted to. Indeed if the HR was flat, the power would more than likely be falling (which is what the OP indicated happened).