Why disable ERG mode on home trainer?

ERG mode, widely used on connected home trainers, promises to simplify your workouts by automatically controlling resistance to maintain a target power output. But in reality, this mode could be limiting you, not only in your sessions, but also in your overall development as a good cyclist. Here's why it's time to rethink its use and adopt a more intuitive and efficient approach if you're used to training on a home trainer.

By Guillaume Judas – Photos: zwift.com, xplova

Reminder: What is ERG mode?

ERG mode is a feature available on some smart home trainers, used to automatically control the resistance of the device during an indoor workout. In ERG mode, the home trainer adjusts the resistance in real time to maintain a preset power (in watts) that you need to produce, regardless of pedaling cadence or speed.

This mode is often used in structured training, such as those offered by platforms such as Zwift, TrainerRoad or Garmin Connect, where specific intervals are programmed (for example, maintaining 200 watts for 5 minutes).

How does it work? The cyclist (or training program) sets a power output to achieve and maintain. If the cadence decreases, the home trainer increases the resistance to maintain the target power, and vice versa if the cadence increases. Unlike SIM (course simulation) or “slope” modes (which simulates a percentagetage climb), ERG mode focuses solely on power, making the pedaling feel constant, even if the virtual terrain changes.

This ERG mode has as its main advantagetagand to allow you to precisely calibrate your training sessions, with constant resistance, whether during the effort phases or during the counter-exercise phases (recovery while maintaining a target power).

Managing your pace: an essential skill stifled by ERG mode 

One of the pillars of performance in cycling, or any endurance sport, is the ability to manage your pace.This skill is not just about maintaining constant power, but about knowing how to listen to your body, adjust your efforts and react to the unexpected. ERG mode, by automating resistance, disconnects you from this reality.

In ERG mode, just pedal: the home trainer adjusts the difficulty to keep you at your target powerThe result? You lose touch with the real sensation of effort. You don't develop your ability to assess intensity, adjust your efforts based on how you feel, or self-regulate to optimize your results. Yet these skills are crucial in racing, where no device will manage your pace for you.

By switching from ERG mode to free-form training, you learn to:

• Assess intensity: understand what a given effort zone represents.
• Adjust your efforts: know when to push harder or ease off.
• Self-regulate: adapt your session according to your form of the day.

These skills will allow you to better manage your pace in competition or know when to accelerate at the right moment during a demanding outing.

Good training is fluid, not static.

ERG mode imposes a rigid structure: a predefined power, a fixed duration, without any flexibility. But effective training must be fluid and adapt to your current physical and mental state. The human body is not a predictable machine. Some days, you're in great shape and able to extend a threshold effort. Other times, fatigue or a lack of energy requires slowing down or changing the focus of the session.

ERG mode, on the other hand, makes no concessions. For example:

• In great shape? You could extend a threshold interval to maximize your gains, but the ERG cuts you off at the programmed duration.
• VO₂ max workouts? These efforts often require starting strong and gradually weakening, which ERG mode doesn't allow, while maintaining constant power.
• Tired? You should be able to reduce the intensity or change focus, but the ERG forces you to maintain the power, even if it becomes counterproductive.

Real progress comes from listening to your bodyIn free mode, you can adapt your efforts in real time, maximize your sessions according to your fitness and avoid turning a workout into a sterile fight against a machine.

ERG mode punishes fatigue

One of the most frustrating flaws of ERG mode is its handling of fatigue.Have you ever failed a session simply because your legs buckled slightly, losing 10 watts for a second? In response, the ERG abruptly increases the resistance to compensate, which can cause your cadence to drop drastically, sometimes by as much as 30 rpm.

Result: you find yourself pedaling in the void, exhausted, unable to get back to the target power without superhuman effort at an absurd speed.

This mechanism punishes fatigue instead of accommodating it. In free mode, however, you can adjust your effort: slightly reduce power, maintain a comfortable cadence, and continue to reap the benefits of the session without unnecessarily exhausting yourself. This approach respects your body's natural fluctuations and promotes sustainable progress.

Train like an athlete, not a robot

ERG mode turns your workouts into a mechanical routine, where you blindly follow the instructions of a machine. But being an athlete is all about learning to listen to your body, adapt, and perform in changing conditions. By abandoning ERG mode, you regain control of your sessions and develop essential skills to excel, whether in racing or during your training.

Conclusion: don't let ERG mode lock you into a rigid, disconnected approachAdopt a workout that's fluid, intuitive, and adapted to your body. This is how you'll truly progress. Adapt. Learn. Perform.

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