You have to go low before you can go high
If I were to ask someone how they plan to get from where they are now to where they want to be fitness-wise on the bike, chances are their answer would be something along the lines of "more power, more volume, more hard work."
It’s not a surprise; many of us go to group rides and feel pinned from the start. We sign up for races only to get shot out of the back. So people think to themselves, "I’m getting dropped at my current level, so I need to train above that." But this doesn't work; it's quite the opposite, actually.
The key to improving your upper zones is to focus on your lower zones first. You need to develop your muscular strength and cardiovascular efficiency. To build each of these things, you need to work on them separately. When you train at a low intensity, you’re teaching the muscle fibers to fire in a specific way — and training the hands, core, and legs to support these neuromuscular connections. By wiring your brain and body in this way, they unconsciously know exactly what to do when it's go-time.
I want you to envision your cycling fitness like a ladder, and each rung represents a specific fitness zone. Each of those fuels systems use a different ratio of fat to sugar. In order to build a tall ladder with many rungs, you need to build the lower rungs so you have somewhere to step when installing the higher rungs. The same applies to fitness zones. You need the well-built lower zones to stand on so you can efficiently ride in the top-end zones with the correct fuel systems.
Most people do the opposite because we are naturally attracted to the top part of the ladder. But without any foundation, the top part of your fitness zone ends up being only as high as you can reach from where you are currently standing. If you try to build out your top levels while you are still standing on the ground there won’t be any space between your low zones and high zones, limiting most of your options as a cyclist.
I've seen it time and time again. You go riding with a friend who is better than you are. So you think to yourself, I’m at my limit, so it’s these power numbers I need to train above. But the place where you are flooded with lactate is not ground zero. That’s not your starting point. Training this way often leads to injuries, burnout, and a lot of pain for not much gain.