If you’ve spent time on an indoor smart trainer, maybe a Wahoo KICKR, Tacx Neo, or even a simple wheel-on unit with added sensors, you might have heard of something called ERG mode. It’s a feature often touted by enthusiasts on Zwift, TrainerRoad, Wahoo SYSTM, and other training apps, but it isn’t always clear how it works or why people love it. If you’re over 50 and looking to maximize your indoor sessions, this guide will steer you through the details of ERG mode in a way that feels approachable and fun, without burying you in technical jargon. Let’s pedal through this step by step.
A Quick Refresher on Smart Trainers
Before we leap into ERG mode, let’s get on the same wavelength about what makes a trainer “smart.” A smart trainer can communicate with external apps (like Zwift or TrainerRoad) through wireless protocols such as Bluetooth or ANT+. This communication allows the app to adjust your trainer’s resistance automatically. It’s light years ahead of the old “dumb” trainers that relied on a static magnet or fluid chamber. With a smart trainer, you can ride virtual routes and structured workouts, all while the machine itself fine-tunes the resistance for you.
ERG mode is the core of that magic. Instead of shifting gears or manually adjusting resistance, the trainer does the adjusting on your behalf. It sounds effortless, right? In many ways, it is. But understanding how it does that—and when you might want to switch it off—can help you make the most of your indoor rides.
ERG Mode – The Basics
ERG stands for “ergometer,” which basically means a device that measures work or energy expended during exercise. The fundamental idea of ERG mode is simple: you set a power target (in watts), and the trainer automatically holds you to that target by adjusting resistance in response to your cadence.
- Power: It’s torque (how hard you press on the pedals) multiplied by cadence (how fast you rotate them).
- ERG Mode in Action: If your workout plan says you need to hold 200 watts for three minutes, the trainer will do everything it can to keep you pedaling at 200 watts. If your cadence drops, resistance goes up. If your cadence rises, resistance goes down.
Think of it as having a robotic cycling coach who says, “Hey, you’re supposed to be at 200 watts,” then cranks resistance up or down so you stay locked on that target. You can change gears if you like, but in many ERG scenarios, you won’t even need to.
Why ERG Mode Matter
Cyclists over 50 often have a couple of priorities: preserving joint health, improving fitness efficiently, and staying motivated. ERG mode can help with all three.
- Reduced Mental Load:
Some folks love to analyze each effort and shift precisely at the right moment. Others just want to hop on, choose a workout from Zwift or TrainerRoad, and let the trainer handle the details. ERG mode removes the guesswork from your intervals—ideal if you’re mentally drained by a long day or juggling family and work commitments. - Consistency in Workouts:
ERG mode forces you to maintain a set power output. This means you won’t accidentally push too hard early on and then fizzle out, which can derail your entire workout. It also prevents you from going too easy when you’re supposed to stress your cardiovascular system or build muscle endurance. - Great for Targeted Training:
If you’ve got a specific fitness goal—like improving your FTP (Functional Threshold Power), working on your VO2 max, or polishing your sprint—ERG mode lets you hit precise power zones for the exact duration your workout demands. This can be especially beneficial if you’re strapped for time. - Less Stress on Joints:
Because the trainer automatically adjusts resistance, you can spin at a comfortable cadence (maybe around 90 RPM or whatever feels smooth) without having to shift under load. It’s a small detail, but for knees and hips that might be a bit sensitive, it can make a difference in comfort.
When ERG Mode Shines
Interval Work: This is the sweet spot for ERG mode. Whether you’re doing short, hard sprints or longer tempo efforts, letting the trainer manage your wattage can keep you laser-focused on the workout. If your plan calls for three-minute intervals at 200 watts and one-minute recoveries at 120 watts, ERG mode will seamlessly transition you from one to the other. You just keep pedaling.
Recovery Rides and Base Miles: It’s not just about intervals. Sometimes you might want to make sure you don’t overcook your legs on a planned easy ride. ERG mode can hold you to a specific low wattage (say 120 watts) so you stay in a recovery zone, even if you’re tempted to chase a virtual rider who speeds past you on Zwift.
Pacing Struggles: If you know you have a habit of going out too hard—who doesn’t sometimes?—ERG mode can keep your ambition in check early in a workout. It can also push you through the last 20 seconds of a tough interval when you might ordinarily throw in the towel. It’s like having a personal trainer shouting: “You can do this! Keep going!”
Drawbacks
Nothing’s perfect, and ERG mode has its quirks.
- Drop in cadence:
Imagine you’re midway through a tough interval, and your legs start to fade. Your cadence drops from, say, 90 RPM down to 75. ERG mode senses a drop in cadence and increases resistance to keep you at your target wattage. Now your legs feel even heavier, so your cadence might slip to 70. The trainer ramps resistance even higher, which can lead to a vicious cycle that forces you to grind to a halt. Not fun. - Potential Over-Reliance:
Because ERG mode sets your power automatically, you might lose out on developing certain real-world cycling skills—like shifting gears effectively, pacing yourself in a headwind, or surging in a race scenario. Too much ERG mode can breed complacency about these aspects of riding. - FTP Fluctuations:
Most structured workouts base their intervals on a percentage of your FTP. But your true FTP can shift daily depending on sleep quality, nutrition, or stress levels. If you’re having an off day, a fixed power target might be too high. Conversely, if you’re feeling super strong, it might hold you back. Of course, you can adjust the workout intensity mid-ride in many apps, but that requires recognizing the mismatch first. - Awkward Sprints:
ERG mode isn’t always quick to respond to sudden power changes. If your workout includes a 10-second sprint, it can feel a bit clumsy waiting for the trainer to catch up. You might not get the full effect of an explosive jump. In those cases, turning off ERG for sprint sessions can feel more natural.
When Should You Turn ERG Mode Off
There’s no shame in flipping that switch to “off” now and then. Here are a few scenarios:
- Short, Sharp Efforts: If your training calls for repeated 10- to 20-second sprints, you might prefer manual control. You can gear up, hammer those pedals, and do it all on your own terms.
- Skill Development: Looking to mimic outdoor riding? Maybe you want to practice shifting or controlling your power output in a realistic way. Turning ERG off helps you stay sharp.
- Pacing Training: Part of real-world cycling is pacing yourself in changing conditions. By manually managing your cadence and gear selection, you can train your instincts for those climbs or rolling courses you’ll see outside.
Getting the Most Out of ERG Mode – Practical Tips
If you’re new to ERG mode, or just want to use it more effectively, consider these pointers:
- Warm Up Properly
If your workout jumps from easy spinning to a high-intensity interval, ERG mode might slam you with a big jump in resistance. Take a few minutes of relaxed pedaling before the intervals start. It gives your legs a chance to loosen up and your mind a moment to settle in. - Keep Your Cadence in a Sweet Spot
Most trainers handle a cadence between 80 and 100 RPM pretty smoothly. If you like to stand up, change your cadence gradually to avoid confusing the trainer’s software. Quick jumps from 90 to 60 RPM can trigger a spike in resistance that leaves you gasping. - Use the Trainer Difficulty Adjustment
Apps like Zwift have a workout intensity slider you can adjust mid-ride. If you’re feeling stronger than usual, push it up a bit. If your legs are screaming because you did heavy yard work yesterday, notch it down a touch. Don’t be shy about customizing your ride so you can finish strong rather than burning out. - Mind the Gear You’re In
Even though ERG mode manages power, staying in a moderate gear (for instance, the big ring up front and somewhere in the middle of the cassette) can help the trainer respond smoothly. Being too high or too low in gearing might lead to big jumps in resistance that feel jerky. - Stay Hydrated and Fueled
It’s easy to forget that indoor training can be hotter and sweatier than outdoor riding. ERG mode doesn’t change that, but sometimes the focus on hitting exact wattages distracts you from grabbing a bottle or a quick bite. Keep water and maybe an energy bar within arm’s reach.
Real-World Cycling Skills vs ERG Mode
One slight contradiction with ERG mode is that it’s brilliant for consistency, yet real-world cycling demands variability. If you plan to tackle a hilly sportive, a club ride, or a multi-day tour, you’ll encounter changing gradients, headwinds, and the need to respond to other riders. That’s why it’s wise to mix up your indoor training.
- Alternate ERG and Non-ERG Sessions: By including a few manual mode workouts each week, you develop pacing skills. You learn when to shift, how to maintain momentum, and when to push over the crest of a hill. This is especially crucial for events where you can’t rely on an app to fix your wattage.
- Outdoor Rides: Whenever possible, complement your indoor routine with a real-world ride. The feeling of road vibration, wind resistance, and gear shifts is something no trainer can replicate perfectly.
Common Questions
1. Can I shift gears in ERG mode?
Yes! You usually don’t have to, but if you prefer a different cadence or want to stand for a bit, shifting can create a more comfortable gear ratio. The trainer will still adjust resistance, though, so it might be less noticeable than when you’re not in ERG mode.
2. Do I need a certain fitness level to use ERG mode?
Not really. ERG mode scales to your abilities. If your FTP is 120 watts, the trainer will hold you at that level just as easily as it would hold someone at 300 watts. The key is knowing your approximate FTP, which you can find through a ramp test or a 20-minute effort test in your chosen app.
3. How do I avoid the cadence drop?
A steady cadence is your best friend. As you feel your legs tiring, try not to let your RPMs plummet. If you notice you’re slowing, shift to a slightly easier gear or stand up carefully for a bit to stretch out. And if you’re really cooked, don’t be afraid to pause the workout or reduce the intensity. It’s better to finish the ride at a reduced wattage than grind to a halt altogether.
Conclusion
ERG mode is a powerful ally for structured training, enabling you to pedal at exactly the right effort without constant mental arithmetic. It’s particularly valuable if you’re an older cyclist who wants an efficient, targeted workout that respects your body and your schedule. But there’s also beauty in riding without the training wheels, so to speak—developing your own pacing, adjusting gears for shifting terrain, and keeping your mind engaged.
The good news is you don’t have to choose one or the other exclusively. You can toggle ERG on for those time-crunched interval sessions and turn it off for longer, more relaxed rides or to practice real-world skills. If you blend the two approaches, you’ll build robust fitness that translates to better performance on the road while still enjoying the convenience of that “set it and forget it” style of training.