I probably need to "slow down". Today I tried to keep my power at about 150 W as consistently as possible, and at times I couldn't manage, and had to drop to just sustaining about 130 W. 100 W is probably quite close to a "walk" in effort (at least for me), and 200 W is a real grind.
This power level seems to be where my pulse rate goes up into the upper 140's, and where my sense of effort crosses the borderline between "conversation speed", and "grunting speed", and it feels quite close to the very edge of what I can currently sustain for longer periods.
One thing almost entirely absent from today's spin was a hill. There were some points where I cranked up the resistence, but I wasn't able to slog it out against this for more than say a minute at a time.
In terms of calories for the 3 25 minute spins so far, it's been 450, 360, 430 (roughly; I'm already forgetting and I don't write it down). Today's only went to 430 because I gave myself an extra 5 minutes of cool off, so that I'm less crippled when I fall off that thing at the end. I still had to walk out most of the tightness.
It's nice having some figures (however inacurate and possibly inconsistent) to use to measure the effect of what you're doing. Today that's about all I'm able to say in favour of spinning, but I'll try to like it better next time. If you're out there running, be glad of it. It's much better than being on some machine, and that's something that's not ever going to change. Relish that fresh air, relish that sky overhead, and the life going on around you. It's still the best.