What is ERG mode?
Smart trainers include a feature called “ERG mode” (ERG is short for ergometer). When turned on, ERG controls the load on the trainer to match a prescribed intensity (power target) during a workout. In other words, no matter what cadence you use or how hard you turn the pedals, the trainer adjusts the load so that your output in watts is exactly the number prescribed on your intervals/workout. All you have to do is pedal. No shifting, no change in cadence.
Why some cyclists prefer to train in ERG mode
Some cyclists believe that hitting power targets is the most important part of a workout (specially if their workouts ignore the importance of cadence changes, transitions, etc.), so they use ERG mode as a way to force them to hit the watts. Other riders don’t want to have to do any “thinking” or shifting during workouts. And many never even thought about the topic, or bought a smart trainer and assumed that ERG mode is simply how all workouts are done.
Reasons for not using ERG
For all the athletes I coach, and for my own training, I never use ERG mode. Here’s why.
Control and muscle activation
Training to control your efforts with your own legs, instead of having the trainer do it for you, is a valuable skill in cycling. Without ERG, you have to work to maintain the power within the target power zones by engaging more muscles in your legs, and by learning to apply and develop torque to be in control.
Control is also important to avoid big power spikes as you transition to a higher power zone, and to avoid power dips as you transition to lower power zones. Learning to hold the tension on the chain with your muscles to control the power as you do these transitions will help you do it on your own when you are not on the trainer, be in at a race, event, or outdoor ride.
Why is it important to avoid these spikes and dips? Because both translate in unnecessary waste of energy. You might think this is small, but in the course of a ride/event/race, it adds all up. By a lot.
Not using ERG makes you aware of how you generate power in the workouts. You practice shifting, changes in cadence, transitions, and body position, all of which are fundamental to performance and speed.
Our workouts incorporate many important skills that translate into more efficient riding (i.e., more power transfer to the pedals), including changes in cadence (low, medium, high) and power, fast and quick changes requiring a fast reaction, etc. ERG would make these very difficult or even impossible to accomplish because of how ERG works.
Lastly, being fast in cycling is not simply about the power you produce. It is about the technique required to produce it. Cycling is a sport, and if you think about any other sport out there, there is always a lot of work on technique (e.g., how to kick, how to throw, etc.) Cycling is no different, so why use an artificial environment that impedes the development of these techniques?
But isn’t ERG mode the reason for buying a smart trainer?
No. Smart trainers are not useless if you do not use ERG. They exist to simulate the changes in terrain when riding a virtual course. These changes are very valuable for when you ride outside and deal with “real” terrain.
If you do workouts in Zwift, for example, and use “workout mode”, all roads will be “flat”. That’s unfortunate, but it is still better than using ERG, because you are still in control of your efforts. I have a Tacx Neo and do all my workouts outside of “workout mode” and outside of ERG, just like I do them outdoors, using the changes in terrain to control the efforts and cadence, while changing body positions (seated vs. standing, etc.)
Give it a try and see the positive changes!
Hope this sheds some light as to why I recommend not using ERG. If you haven’t tried doing workouts outside of ERG, give it a try! Stay with it and be patient as you learn to be in control of your efforts and you will notice the difference in your performance. As our athletes can attest, it is worth it and it has real results!