Finally Figuring Out ERG Mode 🚴🏽‍♂️

Sometime in April, I realized that biking outside wasn’t going to be as accessible as I’d like. So, I bought a “smart” trainer and signed up for Zwift. I’ve found the general riding and racing to be enjoyable. The app tells the trainer to set the resistance based on my cadence, my weight, the road surface and incline and whether I’m in a draft. This helps me forget that I’m on the porch under a fan and not actually doing laps in Central Park or London.

What I’ve really come to value, though, are the workouts and workout plans. The app, working with the trainer, is able to set the resistance for the right amount of time. Additionally, I don’t have to worry about an ill placed stop sign, or watching the road and the bike computer at the same time or remembering what comes next while my brain is Oxygen deprived. I’m definitely progressing in my return to fitness and non-fatness more quickly than if I was just riding outside.

But keeping my cadence and wattage in the right place has been difficult sometimes. Also, I discovered that sometimes, the trainer would appear to malfunction and suddenly make the pedaling almost impossible. Around the time I was considering a strongly worded email to the trainer company about their crappy product, I stumbled across a post about (how to use ERG mode correctly)[https://zwiftinsider.com/erg-mode-in-zwift/]. Turns out that it was a (PBCK)[https://en.wikipedia.org/wiki/User_error] issue all along.

The issue would be that during an interval, the app would ask that I maintain a specific cadence and wattage. I would shift my gears in an attempt to match those numbers and was mostly successful matching the wattage, but often not the cadence. However for some intervals, I couldn’t manage to get in the range. This was especially difficult when lower cadences and higher wattages were requested.

It turns out I was working against the trainer and being impatient. The root issue is that when in ERG mode, the app tells the trainer what wattage we want to maintain and the trainer increases or decreases resistance to try to maintain that wattage. As the rider, I need to match the cadence that I’m begin asked to match, and let the trainer catch up with me (usually takes around 5 to 10 seconds for my trainer setup). I have to ignore the big red warning on the screen of “More Power” or “Less Power” and focus on my cadence. Let it catch up.

Today was the first workout since learning this new information. Sure enough, holding the requested cadence and letting the trainer adjust allowed me to complete the workout successfully and “correctly”. I was finally able to complete the slow cadence, high power intervals correctly as well. I also learned one final, important lesson: because the trainer is using average recent output to decide how to adjust resistance, never stop pedaling. Throwing those zeros into the average will make it seize up almost immediately.