I just listened through the Tri Talk Triathlon Podcast, Episode 61, which among other things touched upon heartrate decoupling to determine sufficient aerobic base.
Heartrate decoupling is calculated as the difference between the average power/heartbeat or speed/heartbeat for the first and second halves of the test. This should be less than -5% for a zone 2 endurance workout of a length relevant to the desired race distance:
The swim durations are the recommendations of David Warden on the podcast, the bike and run durations are those Joe Friel currently use. Subject to change etc.
I am a lucky user of WKO+, and as such I automatically have “Pa/HR” or “Pw/HR” numbers for all training sessions, except swimming because I don't use a heart rate monitor for that. That way training is testing, and testing is training, which is perfect.
Based on my long rides of just over 2 hours and long runs just over 1 hour I should have the endurance for Olympic distance racing, but what does that mean? That I can race an Olympic distance race? Or just get through it without walking the run? Or maybe it's just that I can race it, but needs some sharpening before I can race to my current potential.
I guess the latter. I'll limit myself to sprint distance triathlons this season anyway, so according to this theory I have more than enough base for that.