Earlier quoted context omitted.
I do a lot of running as well and have observed the same effects. After anaerobic sprints or a race of up to 10k, sleep HRV drops / HR is higher and running HR:pace is elevated for up to a week. However, usually this is then followed by some improvement in all of these metrics compared to the baseline before the hard workout. Anaerobic exercise builds/maintains especially fast-twitch muscles, and higher muscle mass h…
That's good you've observed the same effects and definitely agree that anaerobic training improves fitness and teh associated markers over time. When in my teens I did a lot of running but back then I didn't have a HR monitor and probably most of my training was anaerobic and still managed to improve well over the years. I suspect I was taking on high levels of stress which ultimately led me to quit running when I st…
What an amazing improvement to 4:30 pace at 140 bpm btw! I've had a similar relative improvement over the first year when I think about it, from around 7:00 to 5:20-5:30 at 140 bpm. But my training was mostly 1km intervals at high end of zone 3 (still quite below threshold), translating to a lot of tempo running on average, plus one session of 200s or 400s faster intervals per week. Been stuck with little progress for a while though, and was thinking to try a more polarized approach like yours with higher volume; thanks for explaining it!