Why do coaches hate ERG Mode?

Erg mode is convenient. It's precise. It's popular. And a surprising number of experienced coaches quietly — or not so quietly — despise it.

Not because it doesn't work. It does. But because the way most athletes use it allegedly trains the wrong things, creates dependency, and quietly erodes the very skills that make a cyclist fast in the real world.

Below are some common complaints about erg mode, made by the coaches and athletes who say erg mode is bad for you.

I've also included my thoughts and experiences about how I disagree or find these critiques overstated.

Note: I am not addressing the legitimate issues with erg mode that result from not following well-documented "best practices" (gear selection, flywheel considerations, very high power intervals, very short intervals). These are real and merely reflect that no tool or system is perfect in all situations.

It Teaches You to Be a Passenger

This criticism claims that ERG mode removes the athlete from the equation.

In a real ride — on the road, on the track, in a race — power is a consequence of your effort, your tactics, and your read of your body. You decide how hard to push. You regulate intensity based on feel, fatigue, terrain, and competition. That feedback loop between brain, legs, and effort is a trainable skill.

ERG mode severs it.

When the trainer holds the watts, you stop making these decisions. You stop learning to pace. You become a passenger on a machine that is doing the hard work of effort regulation for you. Do this for months, and you can become genuinely worse at self-pacing — because you've stopped practicing it.

Coaches who work with athletes preparing for races, gran fondos, or any real-world event know that pacing is a performance skill. ERG mode doesn't develop it. It atrophies it.

How I disagree:

1. First, making the trainer active in resistance management doesn't "sever" any feedback loop between the "brain, legs, and effort". The rider is still focusing awareness on the cadence and pedal pressure. The goal is still to hold the effort steady and this ALWAYS implies a focus on the key inputs to the target effort: pedal pressure, cadence, and the holistic awareness of the relative and comparative effort from moment-to-moment. Whether the trainer is making micro-adjustments to the resistance is largely irrelevant. In fact, if you are properly maintaining all those inputs, then the trainer won't be actively changing the resistance as you've functionally disabled erg mode.
2. Second, if the real-world skill we're worried about is the ability to effectively manage efforts in an environment of changing external factors (wind, surface conditions, incline, etc.) then the argument should not be against the use of "erg mode" but against the use of "workout mode". On most indoor training platforms (and all "dumb trainers"), being in a "workout" usually means no translation of variable terrain elements to resistance at the trainer. As such, you are always pedaling against a highly stable resistance regardless of the mode you are in. Personally, I think this is the better complaint about indoor structured training. You could make a compelling argument that you should "free ride" your interval workouts so you have to deal with changing terrain inputs.
3. Let's also consider this: how many coaches advise their athletes when doing intervals out on the road to find a stretch of road that makes it easier to sustain a steady effort? Most do so, most of the time. This makes perfect sense because the goal is to create a stable physical demand for the duration of the interval and is an attempt to minimize the disruptions caused by doing so on varying terrain. It seems disingenuous to complain about an indoor solution that provides the exact thing coaches are encouraging their athletes to purposely simulate on the road.
4. Finally, I don't think we should be concerned with comparing trainer efforts to outdoor efforts. Athletes are most likely training indoors because they can't get outside (weather, time constraints, etc.). So, this is not the appropriate comparison. The true comparison is training vs. not training, which is not even up for discussion. At most, one could debate the relative merits of different workout modes: "free ride" vs. "erg mode" vs. "slope/resistance mode".

It Destroys Cadence Awareness

Experienced coaches pay close attention to cadence. It's a window into neuromuscular efficiency, fatigue, and how an athlete is actually generating power. High-level cyclists don't have one cadence — they have a range of cadences they deploy strategically, shifting between them based on gradient, fatigue, and effort type.

ERG mode flattens all of this.

Because the trainer auto-adjusts resistance to match any cadence, athletes stop learning to feel the difference between grinding at 70 RPM and spinning at 95 RPM. They stop developing the neuromuscular coordination to produce the same power at different cadences — a critical skill for real-world riding, where you can't always be in the perfect gear.

Coaches who prescribe cadence-specific work — low cadence strength efforts, high cadence neuromuscular drills — often find that ERG mode athletes struggle to execute these in the real world. The connection between gear, cadence, and feel has been outsourced to a machine.

Why I disagree:

1. Counterpoint #1 from the previous argument applies here as well.
2. Further, to suggest that the athlete can't feel the difference between 300W @ 95 rpm and 70 rpm is ludicrous.
3. In my opinion, erg mode FOCUSES the attention on cadence as that's the primary thing the athlete is controlling. When I am doing an erg mode block, I can ignore power altogether and just focus on pedal pressure and cadence. Furthermore, this gives me a new tool in my arsenal because I can specifically create effort blocks at the same wattage but execute them at different cadences (70, 90, 100rpm, etc.). Arguably, this allows me to work specifically on cadence range in a controlled way that can be difficult-to-impossible on the road.

Perceived Exertion Gets Decoupled from Power

One of the cornerstones of good endurance training is developing a reliable internal sense of effort — the ability to look at a number and feel what it means, or conversely, to feel an effort and know roughly what it corresponds to in watts.

ERG mode breaks this relationship.

Because the machine is always adjusting, athletes never fully experience what it means to produce a given wattage. They experience being held at it. The subtle difference matters enormously. Riding 250 watts on ERG feels different — and teaches different things — than choosing to ride 250 watts in resistance mode, constantly making micro-adjustments to hold that number.

Athletes who train exclusively in ERG mode often report feeling lost when they ride outside. Their power numbers look fine on screen but they can't regulate effort instinctively. They don't know what 250 watts feels like — they only know what it feels like to be forced to produce it.

Why I disagree:

1. First, I want to focus on a dubious claim contained in this argument: "Riding 250 watts on ERG feels different — and teaches different things — than choosing to ride 250 watts in resistance mode, constantly making micro-adjustments to hold that number." In "resistance mode" the resistance from the trainer is fixed and does not change. As such, you use your gears to create the desirable resistance and when combined with a steady cadence you achieve a steady power output. So assuming you don't change gears, the "micro-adjustments" being made to hold 250W are steady pressure on the pedals and steady cadence--EXACTLY the same things you would be doing in erg mode. What are the consequences of failing to maintain these inputs: in the case of erg mode you are going to feel increased resistance through the trainer, in the case of "resistance mode" you will see a decrease in power (and should feel a corresponding decrease in effort). In both scenarios something changes THAT YOU FEEL and you then choose to make a "micro-adjustment" to return to equilibrium. I fail to see how these are fundamentally different.
2. I will admit there may be some extremely subtle difference in feel between 250W (or any other wattage) in erg mode vs. resistance mode. I've often wondered if I am feeling some difference. It may be that the active changes to the trainer resistance precipitated by subtle changes in pedal pressure and cadence are felt as accumulated additional effort. It could be that athletes who have a relatively "good" pedaling style (see souplesse) notice this less than others. This is why it is advised to use a relatively large gear in erg mode to keep the flywheel speed is higher and minimize small accelerations and decelerations due to the dead spot in the pedal stroke). If true, this tells me that erg mode tends to HIGHLIGHT bad pedaling, not create it.
3. Tangentially, I would argue that perceived exertion SHOULD BE decoupled from power! Many athletes mistakenly target specific power numbers even when their body is telling them they can't sustain it. "Back in the day" you almost exclusively relied on perceived exertion to determine whether an effort could be maintained. Perceived exertion is a much more effective measure of your specific capacity at any given moment than watts can ever be.

It Makes Interval Training Feel Deceptively Easy

There's a psychological dimension that coaches find deeply problematic: ERG mode makes hard intervals feel more manageable than they are.

When the machine handles effort regulation, the mental load of a workout drops significantly. You don't have to fight to hold power. You just have to survive. For athletes doing long blocks of structured training, this sounds appealing — until race day arrives and suddenly no machine is holding them at threshold. The mental and volitional demands of choosing to hurt are entirely different, and ERG mode provides no preparation for them.

Racing and riding hard in the real world is partly a mental act. The discipline to push into discomfort and hold power without external constraint is a skill. ERG mode trains the legs. It does not train the mind.

How I disagree:

This argument implies that making training more manageable is a BAD THING. This is simply wrong. One important coaching guideline is to apply the smallest amount stress necessary to achieve the the goal of the workout or training block. The goal IS NOT to make the training as hard as the athlete can handle. As a coach you are trying to apply these resources to achieve the maximal benefit and can't afford to spend them wastefully.

If erg mode makes a particular workout "easier," than it follows that it could also make a "harder" workout feel the same. More physical training stress for the same holistic impact, sounds win-win to me!

Further, the argument suggests that learning how to "survive" an effort is less valuable than having the will to impose the effort on yourself. While both are certainly important (and arguably not mutually exclusive), in my experience racing and intense riding are usually survival games. While I was racing, I spent MUCH more time chasing other athletes that were pushing me to my limits than me imposing the suffering on myself and others (again these two states are two sides of the same coin and have significant overlap from both a physical and mental perspective).

Over-Reliance Masks Developing Fatigue

A more technical concern: ERG mode can disguise meaningful fatigue signals that athletes — and coaches — need to see.

In resistance mode, a fatigued athlete will naturally produce less power. The numbers tell the story. The coach reviews the file and sees that power was depressed, the athlete was struggling, the session should have been easier.

In ERG mode, the athlete is forced to hit the target regardless of how they feel. They grind out the watts because the machine demands it. The session looks perfect in the data — clean power, consistent output. But the internal cost may have been enormous. The athlete has effectively been forced to overcook a day they should have backed off on.

Over a training block, this can compound into accumulated fatigue that's invisible in the data. Coaches describe reviewing athletes' ERG-mode files and seeing what looks like consistent, excellent training — only for the athlete to arrive at a key event flat, overtrained, and confused about why.

How I disagree:

Maybe this is true for self-coached athletes, though it probably doesn't have to be. It absolutely shouldn't be true for coached athletes. This argument implies that the coach and the athlete do not communicate about the workouts except through the recorded data. I am constantly asking athletes how they feel, how the workout felt overall and relative to expectations, and various other subjective data points that help me understand how the training load is being experienced. If the coach and athlete don't have an accurate read on developing fatigue that is a defect in the relationship, not erg mode.

It Prevents Learning to Suffer Productively

Elite coaches are careful to distinguish between useful suffering and pointless suffering. ERG mode, at high intensities, tends to produce the latter.

When a hard effort is externally imposed and you have no agency over it, the psychological experience shifts. You're not choosing to hold VO2 max power — you're being held there. The mental texture of that experience is different, and the coping strategies you develop are different.

Real racing demands that you make a decision — in the pain cave, when every signal says ease off — to stay with the effort anyway. That moment of volition, of choosing discomfort, is trainable. Coaches who work with competitive athletes regard it as one of the most important things to develop in training.

ERG mode never asks you to make that choice. The machine has already made it for you.

How I disagree:

1. This argument seems compelling, but I think is overstates. It seems to suggest that somehow it is easier to ride a maximal or limit effort in erg mode simply because you are being "held there"?!? What? It's not like erg mode does the pedaling for you. You have to make all the same efforts to keep pressure on the pedals and maintain cadence.
2. In fact, I would argue that erg mode contributes an ADDITIONAL hurdle to overcome. If you start to lose the effort, erg mode starts to actively work against you (cadence drops so power drops, trainer increases resistance, cadence drops more, etc. – spiral of death). The "fear" of this outcome is definitely real. In resistance mode, you can let off the effort a little and the only consequence is that power drops a little. There is no instant failure consequence, you only see failure in the data after-the-fact.
3. Quitting the effort is quitting the effort. Just because the mechanism of failure is marginally different doesn't mean you don't confront your mental and physical limits.

Ultimately, erg mode is a tool like any other. It is not inherently better or worse than other tools.

Anecdotally, I spend a LOT of time riding in erg mode when I am training indoors. I even use it when doing unstructured "workouts" to just park me in Zone 2 (one of the primary concerns reflected above). This practice has had zero negative impact on my ability to pace outdoors or otherwise apply the mental side of the riding and racing game.