54M, started running again Nov '24 and background in endurance cycling. Last HM was 2010! Not run since then but cycled >150,000k in that time.
So I started a C25K last Nov after a couple of lazy years, and built up since then. Ran a 22k long run last weekend and first 5k Parkrun today, in 26’13. It was busy so the start was a little slow but overall I paced it fairly well and finished hard. Couldnt really have gone all that much faster. I was pretty done at the end but have experienced worse in races on the bike over the years.
Intervals.ICU gave me loads of FTP, power and time PBs afterwards and suggested a big bump in LTHR from 161 to 168bpm. Seems a LOT? Peak HR on the run was 179 (recorded on a Polar H10 chest strap), and most I have have ever recorded on a max HR run test on a hill 15 years ago was 182.
So, I ran most of the 5k at 171-174bpm after the first 1k and it was hard but sustainable. Recently I have been finding it really hard to stay in my z2 based on the original LTHR despite very low RPE and very slow pace with walk breaks etc. I’ve done many years of z2 cycling work and much of my running the last few years in z2 so know how to pace and stay in zone.
No idea if this bump in LTHR is a good thing to set up, based on this 1 run? It makes a very significant difference to all my training zones obviously and means essentially they all jump up 1 zone eg z2 HR is now pretty much what was z3 etc etc. It does mean that the av HR from last weekends 22k easy run would be z2 now rather than z3 suggested from the old numbers.
Any advice/thoughts appreciated as I’m still fairly inexperienced with my running data. Thanks