Question: I’m confused about the physical effects of base training at 70-80 percent of maximum heart rate. I’ve heard that while in this zone our bodies are building capillaries that supply muscles with blood and nutrients for the harder efforts later in the season. Further, we should avoid any hard efforts in winter, such as climbing, that raise heart rate above this zone. Is this true? By the way, I’m doing squats in addition to my slow rides. — Gary D.

Coach Fred Matheny Replies: It’s important to build an aerobic base with relatively slow rides. But research has invalidated the idea that only slow rides build capillaries. The consensus now is that a mix of slow rides and faster or harder training is best.

Now, about those squats.

Squats enlist fast-twitch fibers, so they negate any capillary-building advantages of your slow rides. Studies show that Olympic weight lifters have the same number of capillaries per muscle fiber as untrained people!

Does this mean squats are bad? No. It’s fine to do them in the off-season — if they are part of a periodized program that builds strength first, then converts it to cycling-specific power with on-bike workouts such as hill climbing and intervals.

After you’ve built weight-room strength, on-bike training will restore your endurance — and you’ll retain the strength base from squats.