If you’ve ever finished a ride thinking, ‘That felt tough—but was it the right kind of tough?’ then ERG mode is about to change everything.
For years, indoor cycling was about spin and sweat. You turned a dial, you pushed the pedals, and you judged your effort by how much you dripped on the mat. But the fitness landscape has evolved. We’ve moved from subjective exertion to training with scientific precision.
At the heart of this revolution is ERG Mode, the game-changing feature that transforms your smart bike from a simple pedal machine into a personalized power coach.
But let's be honest, the transition can be jarring.
Don’t worry. This complexity is precisely why the Speediance VeloNix was engineered to smooth this learning curve.
This guide is your definitive playbook. We’ll walk you through your first four weeks, helping you go from guessing your effort to mastering your watts, turning initial frustration into unparalleled fitness gains.
ERG Mode: What Exactly Are You Switching To?
Think of ERG Mode as the cruise control for watts—a personalized, highly precise power governor for your bike. Your only job is to pedal; its job is to make sure you're outputting the exact power (watts) specified by your workout, every single second.
Unlike a standard resistance mode on a basic stationary bike, where you pick a 'level' and your actual power output fluctuates wildly based on your cadence, ERG Mode is fixed on power.
If your workout demands 200 watts, and you slow your cadence from 90 RPM to 80 RPM, the smart trainer automatically increases the resistance to keep your power at 200 watts. If you speed up, it immediately decreases the resistance. This is the fundamental difference in indoor cycling.
The "Why" - The Unbeatable Benefits of Training with Power
Why go through the effort of mastering ERG Mode? Because it transforms training from a subjective endeavor into a quantifiable science:
- Objective Feedback - There's no more guessing your effort. Your output is measured in real, quantifiable cycling watts.
- Targeted Adaptation - You can precisely stress specific energy systems—aerobic, anaerobic, and neuromuscular— for optimal physiological gains. A 3-minute effort at 105% of your Functional Threshold Power (FTP) will be exactly that, every time.
- Pacing Perfection - ERG Mode training forces you to hold a specific wattage, which is a critical skill for real-world time-trialing, long efforts, and executing structured intervals flawlessly.
- Progress Tracking - Objectively measure fitness improvements over time. As you get fitter, you'll be able to hold higher power at the same perceived effort or heart rate.
What to Expect in Your First 4 Weeks with ERG Mode
Week 1: The "Shock Phase"
Your first ERG mode encounters will feel strange—that's completely normal. The infamous "spiral of death" catches most beginners: your cadence drops slightly, triggering increased resistance to maintain target watts.
This harder resistance drops your cadence further, creating more resistance, until you're grinding at 50 RPM, wondering what happened.
The mental shift is equally challenging. You're surrendering control to the system after years of manual adjusting effort. When resistance spikes, your instinct screams "push harder," but that's counterproductive.
The solution? Maintain a steady cadence between 85-95 RPM, trusting the trainer to handle power. If you get trapped in the spiral of death. Ease up momentarily, spin your cadence back up, and then resume.
Week 2: Learning the Feel of Power
By your second week, you start developing an internal sense of what different wattages actually feel like. You'll notice that 150 watts feels distinctly different from 200 watts, even when you're pedaling at the same cadence. This awareness is crucial because it's teaching your body to self-regulate effort based on power rather than perceived exertion.
The Speediance Power Graphs become invaluable tools during this phase. Watch how your power line stays remarkably steady during ERG mode intervals compared to the jagged, inconsistent lines you'd see from traditional stationary bike workouts.
Resist the temptation to chase "hero watts" during this phase. You might see someone on social media posting about their 300-watt FTP or crushing 400-watt intervals, but remember that power is relative to your body weight and fitness level.
Focus instead on consistency. Hitting your prescribed targets accurately throughout each interval matters far more than occasionally spiking to impressive numbers.
Week 3: Zone Familiarity
Week three is when ERG mode training truly clicks. You're now adapting to structured workouts across different training zones, each designed to stress specific physiological systems:
- Endurance Zone (Zone 2) - These sessions feel conversational and sustainable for hours. In ERG mode, you'll maintain 56-75% of your FTP, building aerobic capacity without accumulating fatigue. The beauty of ERG mode here is that it prevents the common mistake of riding too hard on easy days.
- Tempo Zone (Zone 3) - At 76-87% FTP, tempo efforts are moderately hard but sustainable for 20-60 minutes. These workouts build muscular endurance and improve your ability to process lactate.
- Threshold Zone (Zone 4) - This is where things get serious. At 91-105% FTP, threshold intervals are uncomfortable but sustainable for 8-20 minutes. They're the cornerstone of cycling fitness, improving your lactate threshold—the power you can sustain for roughly 40-60 minutes.
- VO2 Max Zone (Zone 5) - Short, intense efforts at 106-120% FTP that last 3-8 minutes. These brutal intervals expand your cardiovascular system's ability to deliver oxygen to working muscles.
The Speediance VeloNix real-time feedback makes hitting these targets effortless. Your screen displays your current zone, target power, and actual power, along with time remaining in each interval. Color-coded zones provide instant visual confirmation that you're in the right place.
Week 4: Confidence and Calibration
By week four, you're ready for your first real milestone. Performing an FTP (Functional Threshold Power) test on the Speediance VeloNix to recalibrate your training zones.
Your FTP represents the maximum power you can sustain for approximately one hour, and it's the foundation for all zone-based training.
You'll likely notice significant improvements already. Most cyclists see 5-15 watt FTP increases within their first month of structured ERG mode training, simply because they're finally training consistently at appropriate intensities rather than randomly varying their efforts.
Beyond the numbers, you'll identify power consistency trends in your data. Are you starting intervals too hard and fading? Do you need more recovery between efforts? The Speediance system tracks these patterns, helping you understand not just how much power you can produce, but how well you can sustain it.
Now you're ready to integrate ERG mode workouts into your weekly routine with confidence. A typical week might include two or three ERG mode interval sessions, one longer endurance ride, and one or two outdoor rides where you apply your newfound pacing skills to real-world terrain.
How to Set Your Initial Training Zones (Step-by-Step)
Getting your training zones right from the beginning is crucial for effective ERG mode training. Here's exactly how to establish your baseline and adjust as needed:
Step 1 - Complete an FTP Test on VeloNix
You have three testing options, each with advantages:
- Ramp Test (20 minutes, preferred) - This protocol gradually increases power every minute until you can't continue. Your FTP is calculated as 75% of your maximum one-minute power. It's shorter and less psychologically daunting than longer tests, making it ideal for beginners.
- 20-Minute Test - After a thorough warmup, ride as hard as you can sustain for 20 minutes. Your FTP equals 95% of your average power during that effort. This test is a classic protocol that provides reliable results.
- 60-Minute Test - A full-hour time trial effort where your average power equals your FTP directly. This is the most accurate but also the most brutal option, typically reserved for experienced athletes.
Step 2 - Calculate Your Zones
Once you have your FTP, the Speediance app calculator automatically determines your training zones:
- Zone 2 (Endurance): 56-75% FTP
- Zone 3 (Tempo): 76-87% FTP
- Zone 4 (Threshold): 91-105%
- Zone 5 (VO2 Max): 106-120% FTP
- Zone 6 (Anaerobic): 121% FTP and above
Step 3 - Adjust Based on Feel (First 2 Weeks)
While FTP tests are reliable, everyone responds slightly differently to power-based training. Use these guidelines to verify your zones feel appropriate:
- Zone 2 should allow comfortable conversation. If you're breathing too hard to talk in complete sentences, your zones might be set too high.
- Zone 4 should be uncomfortable but sustainable for 20+ minutes when fresh. You should think, "This is hard, but I can hold it for the duration."
- Zone 5 should be very hard—manageable for 3-8 minutes maximum. These efforts should leave you genuinely exhausted.
If your zones feel drastically wrong—Zone 2 feels too easy or Zone 4 is absolutely crushing—consider retesting your FTP after a few more adaptation workouts.
Step 4 - Update Monthly
Your fitness isn't static, especially when you're new to structured training. Expect FTP increases of 5-20 watts in your first few months of consistent ERG mode training. Re-test every 4-6 weeks to keep your zones aligned with your improving fitness.
The Speediance VeloNix tracks your progression automatically, monitoring trends in your power data and even suggesting when you might be ready for a retest based on your workout performances.
When to Use (and Not Use) ERG Mode
While ERG mode is incredibly powerful, it's not always the right tool for every workout. Understanding when to use it—and when to switch it off—will maximize your training effectiveness.
1. Perfect ERG Mode Scenarios
Ideal workouts for ERG include sweet spot intervals that target your threshold precisely, Zone 2 endurance rides that build aerobic capacity without overdoing it, tempo efforts, and long 20+ minute steady state rides for stamina.
2. When to Toggle ERG Off
Certain workouts require more freedom than ERG allows. Sprint intervals lasting 10–30 seconds need immediate resistance changes for explosive acceleration, which ERG can’t respond to fast enough.
Maximal VO2 max efforts and race simulations benefit from natural power fluctuations to develop pacing instincts and tactical skills. Skill drills like cadence variation and standing-seated transitions are also better done outside ERG.
Why Speediance Is the Ideal ERG Mode Companion
The transition to ERG Mode can be rocky on older or basic smart trainers. The Speediance VeloNix is engineered specifically to make your first four weeks (and beyond) as smooth and effective as possible.
The VeloNix uses cutting-edge, AI-driven digital resistance technology. This means the adjustment of resistance during ERG Mode is significantly smoother and more responsive than the magnetic or fluid-based resistance found in traditional smart trainers.
This difference eliminates the jarring, sudden resistance changes that contribute to the "spiral of death" on less sophisticated equipment. Speediance calibration ensures a near-instantaneous, seamless resistance control to keep you hitting your target cycling watts perfectly.
Train Smarter, Not Harder
Mastering ERG Mode is the single most important step in unlocking the efficiency and effectiveness of your smart trainer.
Embrace the initial challenge. You'll encounter an inevitable "ERG shock" early on, but focusing on cadence and trusting the system transforms that challenge into consistent power gains you never imagined possible.
Speediance doesn’t just enable ERG Mode; it elevates it—turning a clinical feature into a personalized, intelligent training experience. Within weeks, you’ll wonder how you ever trained without it.
Ready to experience the power of ERG mode training? Explore the Speediance VeloNix Smart Bike or book an exclusive demo to feel the difference in person.
Frequently Asked Questions:
1. Does the gear I use on my bike matter in ERG Mode?
Yes, it significantly matters. Easy gears simulate climbing/VO2 Max (low inertia); hard gears mimic fast flat-road/Time Trial (high inertia). Choose your gear for the desired ride feel.
2. I feel like ERG Mode is harder than riding outside at the same wattage. Why?
ERG Mode is relentless. Outdoors allows micro-rests (coasting/soft-pedaling) that you don't get indoors. The consistent, non-stop workload in ERG Mode simply accumulates more fatigue over time.
3. Is it okay to use the Workout Intensity/Slope setting to adjust my power target in ERG Mode?
Yes, it's a vital training tool! Adjusting intensity 5-10% lets you manage daily fatigue. This ensures you complete the workout’s physiological goal without risking burnout on a bad day.
4. Can ERG Mode help me improve my pedaling efficiency?
Indirectly, yes. To avoid the dreaded "Spiral of Death" caused by cadence drops, ERG Mode forces you to naturally develop a smoother, more consistent pedal stroke over time.
5. Should I stop using ERG Mode completely before a big race or event?
Reduce reliance, but don't stop completely. Real-world racing requires manual shifting and pacing skills. Incorporate Level Mode/free-ride workouts to practice gear management and hitting targets.
References:
Bell, T. (2023, October 25). ERG mode explained: what it is, how to use it, and when you should turn it off. BikeRadar. https://www.bikeradar.com/advice/fitness-and-training/erg-mode
Peralta, M. (2025, September 17). The Ultimate Employee Resource Group Training Guide for 2025. Togetherplatform.com; Together Platform. https://www.togetherplatform.com/blog/employee-resource-group-training
Wahoo Sports Science. (2022, September 13). ERG Mode: Indoor Cycling Training Tips - Wahoo Fitness Blog. Wahoo Fitness Blog. https://www.wahoofitness.com/blog/indoor-cycling-tips-for-training-in-erg-mode/
Schlange, E. (2025, September 30). All About ERG Mode in Zwift Workouts. Zwift Insider. https://zwiftinsider.com/erg-mode-in-zwift/
