The 80/20 Rule: Ride Easy to Get Faster

If you only remember one idea about endurance training, make it this one: most of your riding should be easy. Researchers who studied the training diaries of top endurance athletes, most famously Stephen Seiler, found the same pattern again and again. Roughly 80% of their training was at a low, comfortable intensity, and only about 20% was hard.

That surprises a lot of people, because it feels like every workout should leave you exhausted. But easy riding is where your body builds its aerobic engine: more capillaries, more mitochondria, a stronger heart. Hard riding sharpens that engine, but it also costs a lot of recovery. Do too much of it and you stop getting fitter.

The trap: the grey zone

The most common mistake is not riding too hard on hard days. It’s riding medium-hard every day. When every ride is “kind of hard”, your easy days aren’t easy enough to recover, and your hard days aren’t hard enough to push your limits. Coaches call this the grey zone, and it’s where a lot of indoor riders get stuck.

A good test: on an easy ride you should be able to hold a conversation, or at least speak in full sentences. If you can’t, back the resistance off.

What 80/20 looks like on a spin bike

• Easy rides (the 80%): resistance in the green and low yellow, smooth cadence around 85–95 RPM. Endurance 45 and Easy Spin 30 are built for this.
• Hard rides (the 20%): short efforts up into the red, with real recovery between them. 30/30s, Pyramid 30 and the hill rides fit here.
• Never two hard days in a row. Put an easy ride or a rest day between them.

You don’t need to count minutes precisely. If you ride four or five times a week, one or two of those rides should be hard, and the rest should feel almost too easy. That’s the point.

Does it work for regular riders?

Most of the research is on trained athletes, so it isn’t proof for everyone. But the core advice, that most riding should be genuinely easy and a small share genuinely hard, shows up in almost every coaching approach. It’s also kinder to your joints, and much easier to stick with.

Next: Building a weekly plan puts these rides into a simple week.