Today I worked at low-cadence/high-gear pedaling. That way I can go at a pace that I'd like to maintain for a century ride, and my heart rate stays in lower zone 4. That's great, but next week I must do some high-cadence/low-gear work. That's important too, for spinning my way uphill. Riding uphill in a hard gear is hard on the knees, thus the need for quick pedaling in an easy gear.