Zone 2 in a sauna

Zone 2 is the easy aerobic effort, the pace where you can talk in full sentences, which for an introvert was never the selling point. Every endurance book says to spend most of your training there, and in September 2023 we started doing it instead of nodding along, and the problem with that is where we live.

In humidity my heart rate climbs through a session even when the pace doesn't, because the body is working to cool itself and can't, so the heart works harder to push blood to the skin. An effort that starts in zone 2 at 5:30 a.m. is out of it by 7 without the pace changing at all, and I've watched it happen on the watch more mornings than I can count. So running in zone 2 here came down to one of two things for us. Either we slowed down as the morning warmed up, which felt ridiculous when the pace was already slow, or we accepted that the back half of the session wasn't zone 2 anymore and planned for it. We did both, depending on the day, and neither one felt wrong, and the only version that didn't work was pretending the drift wasn't happening.

What it looked like was the runs getting slower, slower than felt reasonable, slow, okay, embarrassingly slow, slow enough that the first few weeks were a small argument with my ego every single morning. Was I really going to run that slowly on purpose? I was, and I did, and I didn't love it, but the runs also got longer without leaving a mark, and when the hard sessions came there was something behind them that hadn't been there before. We put one hard bike session in that month, a VO2 max effort on the trainer, mostly to remember what hard felt like, and that was the only one, as the rest was easy, early, and long.

At this age the easy work is where the volume lives, because the hard sessions cost more to recover from than they did at thirty, so there are fewer of them, and the base has to come from somewhere. For us it came from a lot of boring mornings at a pace that would embarrass a twenty-year-old, and I'm fine with boring, since boring is my whole thing (routine-based, predictable, and happy about it). Once we started treating the easy days as actually easy, the heat quit winning every session, though it still won some. The trainer in the room off the bedroom helped with this more than I expected, because on the trainer there's no drift from the sun, only from the fan not being big enough.