Incredible vs TrainingPeaks: CTL/ATL Fitness Modeling Without the Complexity or Cost

Incredible is a free health intelligence app for iPhone and Apple Watch with readiness scoring, strength training, and CTL/ATL fitness modeling. TrainingPeaks is the industry-standard endurance training platform with coaching tools, workout planning, and the Performance Management Chart (PMC) that popularized CTL/ATL. Both use the same fitness modeling science. They serve very different audiences at very different price points.

At a Glance

Feature	Incredible	TrainingPeaks
Price	Free	Free basic, Premium $19.95/month or $134.99/year
CTL/ATL fitness modeling	Yes	Yes (PMC, Premium only)
TSS/training load	Yes	Yes
Readiness score	Yes (biometric + training load)	TSB only (training-load based, not biometric)
HRV tracking	Yes (native)	Display only (imports from external apps)
Sleep analysis	Yes	No
Strength training	Yes (gym logging)	Yes (added, but strongest for endurance)
Muscle group recovery	Yes	No
Structured workout builder	No	Yes
Coaching marketplace	No	Yes
Race planning	No	Yes
Body temperature	Yes	No
SpO2 tracking	Yes	No
Respiratory rate	Yes	No
Apple Watch app	Yes (native)	No (syncs structured workouts to native Workout app)
Platforms	iOS/watchOS	iOS, Android, Web
Account required	No	Yes
On-device processing	Yes	No (cloud-based)

The Core Difference

TrainingPeaks is where CTL/ATL modeling lives in the public imagination. The Performance Management Chart -- showing Chronic Training Load (fitness), Acute Training Load (fatigue), and Training Stress Balance (form) -- has been the gold standard for endurance training periodization for over a decade. Coaches build training plans around it. Athletes race based on it.

But TrainingPeaks was built for a specific user: the coached endurance athlete training for a specific event. The platform assumes you have a power meter or GPS device, that your training is primarily cardio, and that you are willing to invest $19.95/month (or $134.99/year) for Premium access. The PMC, advanced analytics, and full planning tools are all behind the Premium paywall. If you are a triathlete with a coach preparing for an Ironman, TrainingPeaks is hard to beat.

TrainingPeaks has expanded to include strength training -- you can now log strength sessions, not just cardio. But the platform's strength is still endurance. Its TSS calculations, structured workout builder, and coaching ecosystem are all optimized for swim/bike/run. Strength training is supported but not the core competency.

Incredible takes the CTL/ATL math -- the same exponentially weighted moving averages, the same fitness/fatigue relationship -- and makes it accessible to regular people who train with a mix of cardio and strength. No coaching platform. No event calendar. No power meter required. Just your Apple Watch data and your logged workouts feeding into a fitness score you can actually understand. It also adds something TrainingPeaks lacks: a biometric readiness score derived from HRV, sleep, and resting heart rate. And it is free.

Fitness Modeling

TrainingPeaks pioneered the Performance Management Chart. CTL (Chronic Training Load) represents your fitness -- the rolling average of your training stress over roughly 42 days. ATL (Acute Training Load) represents your fatigue -- the rolling average over roughly 7 days. TSB (Training Stress Balance) is CTL minus ATL and indicates your "form." This model has been validated over decades of use in cycling, running, triathlon, and swimming. All of this requires a Premium subscription ($19.95/month or $134.99/year).

The catch: TrainingPeaks calculates training stress primarily from power and pace data. While strength training is now supported on the platform, the TSS (Training Stress Score) calculations remain most accurate for cardio activities where power or pace data provides precise load measurement. A heavy lifting session still generates less precise training stress values than the same duration on the bike with a power meter.

Incredible uses the same underlying CTL/ATL mathematics but extends the inputs. Cardio training load is calculated from heart rate and duration (similar to hrTSS in TrainingPeaks). Strength training load is calculated from exercise volume -- sets, reps, weight, and muscle groups worked. Both feed into the same fitness model. Your fitness score reflects your complete training picture, not just the cardio portion.

For pure endurance athletes training with power meters, TrainingPeaks' power-based TSS is more precise. For anyone who mixes cardio and weights -- which is most people who train regularly -- Incredible's model is more complete.

Readiness and Recovery

Incredible provides a daily readiness score (0-100) that integrates overnight HRV, resting heart rate, sleep quality, and your recent training load. This is an automated, daily answer to "how recovered am I?" -- the question every athlete asks before training. The score combines training-load-based fatigue with biometric recovery signals, giving you a more complete picture than either metric alone.

TrainingPeaks offers TSB (Training Stress Balance) as a proxy for readiness. TSB tells you whether your recent training load exceeds your fitness base -- a useful signal, but purely mathematical, not biometric. It does not know how you slept, what your HRV did overnight, or whether you are fighting off a cold. TrainingPeaks can display HRV data imported from third-party apps, but it is display only -- the platform does not synthesize HRV into a readiness score or use it in any algorithmic way.

Experienced athletes and coaches interpret TSB alongside external data to make recovery decisions. Incredible automates that interpretation for people who train without a coach -- which is most people.

Strength Training

Incredible includes full strength training logging with Apple Watch control. Exercise library, set-by-set tracking, templates, and muscle group tagging. All of this data feeds into both your readiness score and your fitness model. Your deadlift session on Monday shows up as meaningful load in your CTL/ATL model, not as a footnote.

TrainingPeaks now includes strength training support -- a meaningful expansion from its endurance-only roots. You can log strength workouts on the platform. However, the strength experience is still secondary to the endurance tools. There is no dedicated Apple Watch app for gym logging; TrainingPeaks syncs structured workouts to the native Apple Workout app but does not provide a gym-logging interface on the wrist. The platform's structured workout builder, coaching marketplace, and analytics remain most powerful for swim/bike/run.

For pure endurance athletes, TrainingPeaks' strength addition rounds out an already comprehensive platform. For lifters who also do cardio, Incredible's strength-first approach with recovery integration is more useful.

Vitals

Incredible tracks six vitals with historical trends: HRV, Sleep Score, Resting Heart Rate, Body Temperature, SpO2, and Respiratory Rate. These are read from Apple Watch and HealthKit, displayed with trend context, and integrated into the readiness algorithm.

TrainingPeaks does not natively track vitals. It can display HRV data imported from third-party apps, and it accepts some biometric data via syncing services, but it does not have its own biometric tracking or a dedicated Apple Watch app for data collection. The platform is built around training files (FIT, TCX) from bike computers and GPS watches, not wrist-worn biometric sensors.

Accessibility and Learning Curve

Incredible is designed to be understandable without a sports science background. Your fitness score goes up when you train consistently and down when you do not. Your readiness score tells you if you are recovered. The CTL/ATL model runs in the background -- you do not need to know what those acronyms mean to benefit from the output.

TrainingPeaks assumes a level of knowledge. Understanding TSS, IF, NP, CTL, ATL, TSB, FTP, and how they interact requires either a coaching background or significant self-education. This is the trade-off of a professional-grade tool: it is powerful but not immediately accessible. Many self-coached athletes pay for TrainingPeaks Premium but only use a fraction of its features because the learning curve is steep.

Pricing

Incredible is free. Every feature -- fitness modeling, readiness scoring, strength training, all six vitals -- is available with no subscription, no account, no ads. Tip jar only.

TrainingPeaks offers a limited free tier (view workouts, basic calendar) and a Premium tier at $19.95/month or $134.99/year. The PMC, advanced analytics, and full planning tools all require Premium. Coaches pay separately for their TrainingPeaks coaching accounts. Over a year, that is $135-$240 for the athlete depending on monthly vs annual billing.

The pricing reflects TrainingPeaks' positioning as a professional coaching platform. If you use it with a coach who builds your plans, analyzes your data, and adjusts your training, the cost may be justified by the coaching ecosystem. If you are a self-coached athlete who mainly wants to see your fitness trend and know when to rest, $135+/year is a lot for a chart you can get for free.

Privacy

Incredible processes everything on-device. No account, no cloud sync, no data uploaded.

TrainingPeaks requires an account and stores training data in the cloud. This enables coach-athlete sharing, cross-device access, and the third-party integrations that make the platform powerful -- but it means your training data lives on external servers.

Who Should Choose What

Choose Incredible if you want CTL/ATL fitness modeling that includes both cardio and strength training, a daily readiness score based on actual biometrics, and a native Apple Watch experience -- without paying anything. Incredible makes the science of training load accessible without requiring coaching knowledge, a power meter, or a subscription.

Choose TrainingPeaks if you are a dedicated endurance athlete with a coach, training for specific events, and using power-based metrics. TrainingPeaks' structured workout builder, coaching marketplace, race planning tools, and power-calibrated TSS are purpose-built for that use case and remain unmatched in depth. If your training is primarily endurance and you work with a coach, TrainingPeaks' ecosystem justifies the cost. It also supports Android and web, unlike Incredible.