You load up a session, the numbers lock in, and all you have to do is turn the pedals. The power stays exactly where it should be. It feels controlled. Productive. Efficient.
And to be fair, it is useful.
But if a cyclist spends too much of their training in ERG mode, something important starts to go missing. Not fitness—you’ll still get fitter. But the kind of fitness that actually transfers to the road, to races, to real-world riding.
Because cycling, at its core, isn’t controlled. It’s constantly changing. And that’s where ERG can quietly hold you back.
One of the first things that disappears in ERG mode is pacing.
Out on the road, pacing is a skill you develop over time. You learn how an effort should feel early, how to hold something back, how to finish strong. You make small decisions every few seconds—sometimes without even realising it.
ERG takes that away. The effort is prescribed and enforced. You’re no longer learning how to pace—you’re simply complying. And that difference matters when you’re faced with a long climb, a headwind, or the back half of a race where pacing decisions determine the outcome.
Closely tied to that is the ability to control power.
Producing power isn’t the same as controlling it. Outdoors, holding a steady output requires constant micro-adjustments—pressure through the pedals, cadence changes, gear selection. It’s an active process.
In ERG mode, that responsibility disappears. The trainer smooths everything out. Over time, you can lose that feel for what it actually takes to hold power on your own.
And then there’s the reality of terrain.
Even the most “steady” outdoor ride isn’t truly steady. The gradient shifts slightly. The wind changes direction. The road surface varies. You respond instinctively, adjusting effort without thinking.
ERG removes all of that. It turns cycling into a perfectly flat, perfectly predictable experience. Which is the exact opposite of what you’ll encounter outside.
That predictability also changes how engaged you are mentally.
It’s easy to switch off in ERG mode. You can watch something, scroll your phone, let the session tick by while the trainer does the hard work of holding you accountable to the numbers.
But real riding demands attention. It demands presence. It demands that you stay connected to what you’re doing. If that skill isn’t being trained, it shows up when things get tough or unpredictable.
There’s also a missing piece when it comes to responding to changes in effort.
Outdoors, power isn’t a straight line. You surge over rises. You respond to others. You push a little harder out of corners. Then you settle again. That variability is part of the sport.
ERG mode flattens everything into a single demand. You don’t practise lifting the effort or easing it back—you just sit on one number. Which means those transitions, those changes in rhythm, never get trained.
Fatigue behaves differently too.
In the real world, when fatigue builds, your power starts to drift. Maybe it drops slightly. Maybe you have to fight to hold it. Maybe you make a call to adjust.
ERG doesn’t allow that conversation. It holds the target constant, and you either keep turning the pedals or you don’t. That can create a disconnect between how fatigue actually feels and how you respond to it.
Cadence is another subtle one.
On the road, cadence and power are closely linked. Change one, and you influence the other. You learn what feels efficient, what feels sustainable, what works for you.
ERG decouples that relationship. You can spin faster or slower and the trainer simply adjusts resistance to keep power constant. It removes an important layer of feedback that helps cyclists refine their efficiency.
The same goes for gear selection.
Outside, choosing the right gear is part of the skill set. It affects cadence, torque, and how smoothly you apply power. It’s something experienced riders do almost automatically.
In ERG mode, it becomes irrelevant. And like any skill that isn’t practised, it fades.
There’s also a tendency in ERG mode to grind through efforts even when form starts to slip.
Because the trainer is holding you to a number, you can end up completing intervals with poor technique—hips rocking, upper body tense, pedal stroke deteriorating. You’re hitting the target, but not necessarily in a way that builds good habits.
And over time, that can limit how well your strength transfers to real riding.
Finally, there’s the issue of variety—specifically neuromuscular variety.
Outdoor cycling naturally exposes you to different cadences, different torque demands, different patterns of muscle recruitment. It’s constantly changing, even within a single ride.
ERG mode is far more static. The demand is fixed, the response is fixed, and that variability is reduced. Which can mean you’re not developing the full range of skills and adaptations that cycling requires.
This is where a more interactive indoor setup can make a real difference.
If you’re doing the bulk of your riding indoors, you want an environment that still asks something of you—where you’re making decisions, adjusting effort, and staying engaged.
That’s exactly how we use Velocity within Qwik Kiwi Coaching.
We run two squad-based sessions each week:
- Tuesday at 6 a.m. (NZ time) — a sharper session, 45 minutes or less
- Thursday at 6 a.m. (NZ time) — around an hour, sometimes a touch longer, sometimes a touch shorter
These aren’t “set and forget” ERG workouts. You’re actively riding the session—responding, adjusting, working through changes in intensity in a way that better reflects real cycling.
If you’ve been relying heavily on ERG mode, it’s a great way to reintroduce that missing layer of skill without losing the structure of indoor training.
You can try it out here with a 14-day free trial:
👉 http://app.vqvelocity.com/join?a=rhs956
None of this means ERG mode is bad.
Used well, it’s a powerful tool. It’s brilliant for learning structure, for hitting key intensities, for removing guesswork—especially for newer athletes.
But it’s just that—a tool.
And like any tool, if you rely on it too much, you limit what you develop.
The goal isn’t to avoid ERG mode. It’s to make sure it doesn’t replace the skills that actually make you a better cyclist.
Because when you head outside, the road doesn’t care what your trainer can do for you.
It only reflects what you can do for yourself.