How TrainCraftWorks
Learn how to use every feature to get the most out of your training. From predicting race times to building custom workouts, we've got you covered.
Race Predictor
Predict your race time using physics based simulation. Upload routes, configure race parameters, get accurate time estimates.
Workout Builder
Visual drag and drop interface to create custom workouts. See power zones in real time, export to any platform.
Adaptive Planning
AI detects missed workouts and replans your training automatically using fatigue science (CTL/ATL/TSB).
Progress Tracking
PMC charts with Workout Score, CTL, ATL, TSB. Understand fitness, fatigue, and form to optimize training load.
Route to Workout
Convert GPS routes from Strava/Garmin into indoor workouts using cycling physics. Train for real climbs indoors.
Training Plans
Multi-week periodized plans with proper base/build/peak/recovery phases. Browse library or build your own.
Predict your race time with physics based accuracy
Our Race Predictor uses advanced cycling physics simulation to estimate your race performance based on real power, weight, aerodynamics, and terrain data.
What is it?
The Race Predictor is a physics based simulation engine that calculates how fast you'll complete a race based on your physiological data (FTP, weight), equipment (bike type, aerodynamics), and race conditions (terrain, surface, weather). Unlike simple extrapolations, it models real cycling physics: air resistance, rolling resistance, gradient effects, power decay over time, and fatigue accumulation.
How to use
Upload your race route
Import a .fit or .gpx file from Strava, Garmin, or RideWithGPS. The system will analyze elevation, distance, and surface type.
Configure race parameters
Set your FTP, weight, bike type (road, TT, gravel, MTB), race type (time trial, gran fondo, criterium), number of laps, and intensity strategy (steady, negative split, all-out).
Get your prediction
See estimated finish time, average speed, power requirements, split times for each segment, and pacing advice. Adjust parameters to explore different scenarios.
Calibrate for accuracy (optional)
Import past rides to calibrate the model to your specific physiology and equipment. The more data you provide, the more accurate predictions become.
Why use it?
- Set realistic race goals: Know what time is achievable based on your current fitness
- Plan race strategy: See which segments require the most power and plan pacing accordingly
- Compare equipment: See how different bikes affect your finish time (e.g., road vs TT bike)
- Train for specific events: Convert the route into a workout and practice the exact power profile
⚠️ Important: Predictions are estimates based on assumptions. Real race performance is affected by weather, drafting, nutrition, mental state, and many other factors we cannot model. Use predictions as training guidance, not guarantees.
Create custom workouts visually
No spreadsheets, no confusing syntax. Just drag, drop, and adjust. See your power zones in real time.
What is it?
The Workout Builder is a visual interface for creating structured interval workouts. Instead of writing text files or filling spreadsheets, you add intervals graphically, adjust power and duration with simple controls, and instantly see the workout profile. It's designed to match how you think about training, not how computers process data.
Sweet Spot 2×20
Classic threshold builder
Power Profile
How to use
Set your FTP
Enter your Functional Threshold Power so all zones are calculated automatically.
Add intervals
Click "Add Interval" and choose type: Warmup, SteadyState, Intervals, Cooldown, FreeRide. Each type has different options.
Adjust power and duration
Use sliders or input fields to set power (% of FTP) and duration. See the graph update in real time.
Export to any platform
Download as .zwo (Zwift), .erg (TrainerRoad), .fit (Garmin), or .mrc (any trainer app). Use your workout anywhere.
Why use it?
- No spreadsheets: Create workouts the way you think about them, not the way computers need them
- Instant feedback: See exactly what the workout will look like before you ride it
- Platform freedom: Export to any trainer app, no lock-in to a single ecosystem
- Build your library: Save custom workouts and reuse them in training plans
AI replanning when life gets in the way
Missed workouts? Got sick? Life happened? Our AI detects disruptions and intelligently adjusts your plan using real fatigue science.
What is it?
Adaptive Planning is our AI powered replanning system. It monitors your training, detects when you've missed workouts or deviated from the plan, analyzes your current fitness and fatigue levels (CTL/ATL/TSB), and automatically suggests plan adjustments to keep you on track toward your goals. It's like having a coach who understands that real life happens and knows how to adjust accordingly.
How it works
Detection
The system automatically detects missed workouts, partially completed sessions, or significant deviations from planned intensity.
Analysis
AI analyzes your current CTL (fitness), ATL (fatigue), TSB (form), and how far off-track you are from the original plan goals.
Replanning
The system generates a new plan that accounts for your current state, adjusts training load to avoid overtraining, and recalculates the timeline to your goal event.
Your approval
You review the suggested changes and decide whether to accept the new plan or continue with the original. AI suggests, you decide.
Why use it?
- Life happens: Don't abandon your plan when you miss a few workouts. Get intelligent adjustments instead.
- Avoid overtraining: If you've been sick or exhausted, the system reduces load appropriately
- Stay on track: Keep progressing toward your goal event even when plans change
- Science-backed: Uses proper training science (CTL/ATL/TSB), not guesswork
Understand fitness, fatigue, and form
PMC charts with Workout Score, CTL, ATL, TSB. Real training science to optimize your training load.
What is it?
Progress Tracking is our Performance Management Chart (PMC) system. It tracks your training load over time using scientifically validated metrics: Workout Score (training stress), Weighted Power (normalized power accounting for variability), Intensity Ratio (relative intensity), CTL (long-term fitness), ATL (short-term fatigue), and TSB (form/readiness to perform).
Understanding the Metrics
Measures the training stress of a single workout. Calculated from duration and intensity (Intensity Ratio). A harder, longer workout has a higher score.
Power metric adjusted for variability. Hard efforts count more than easy ones. Shows the "true" physiological cost of variable power output.
Weighted Power divided by FTP. Shows how hard the workout was relative to your threshold. IR > 1.0 = above threshold.
Your long-term fitness trend (~42 day average of Workout Scores). Higher CTL = more fit. Build this gradually to improve performance.
Your short-term fatigue (~7 day average of Workout Scores). Higher ATL = more fatigued. Needs to be managed to avoid overtraining.
Your form/readiness (CTL - ATL). Negative TSB = fatigued but building fitness. Positive TSB = fresh and ready to perform. Taper before events to raise TSB.
How to use
Log your activities
Import rides from Strava/Garmin (.fit files) or manually log workouts. The system calculates Workout Score for each activity.
Watch your trends
See CTL (fitness) rise gradually over weeks. Monitor ATL (fatigue) to avoid overtraining. Check TSB (form) before key events.
Adjust training load
If ATL is spiking too high, reduce intensity. If CTL is plateauing, add more stress. Use the data to make informed decisions.
Taper for events
Before key races, reduce training volume to raise TSB into positive territory. Arrive fresh and ready to perform.
Why use it?
- Avoid overtraining: See fatigue building before you crash. Back off when ATL spikes.
- Optimize performance: Peak at the right time by managing fitness and freshness
- Make informed decisions: No more guessing whether you're training too hard or too easy
- Proven science: These metrics are used by professional coaches and athletes worldwide
Train for real routes indoors
Convert GPS routes from Strava or Garmin into realistic indoor workouts using cycling physics.
What is it?
Route to Workout converts real GPS routes into structured indoor workouts. Upload a .fit or .gpx file from your target race or favorite climb, and we'll use cycling physics to calculate the power required at each point based on gradient, surface type, and your bike setup. The result is a workout file you can ride on any smart trainer, experiencing the same power profile as the outdoor route.
How to use
Upload GPS route
Import .fit or .gpx file from Strava, Garmin, or download route from RideWithGPS. Must include elevation data.
Set parameters
Configure your FTP, weight, bike type, target intensity. The system will calculate required power for each segment.
Review workout profile
See the power profile mapped to the elevation profile. Adjust intensity if needed to make it realistic for indoor training.
Export and ride
Download as .zwo, .erg, or .fit and load into your trainer app. Ride the route without leaving home.
Why use it?
- Race preparation: Train for the exact climbs and terrain you'll face on race day
- Recreate best rides: Import your PRs from Strava and repeat the same effort indoors
- Year-round training: Practice outdoor routes when weather is bad
- Realistic simulation: Not just random intervals—actual power demands based on real terrain
Multi-week periodized training plans
Structured plans with proper base/build/peak/recovery phases. Browse library or build your own.
What is it?
Training Plans are multiweek structured programs designed using proven periodization theory. Each plan follows a progression: Base building (endurance foundation) → Build (intensity and specific fitness) → Peak (race preparation) → Recovery (adaptation). Plans can be browsed from our library or created from scratch using the plan builder.
How to use
Choose a plan
Browse the library for plans matching your goal: FTP improvement, century ride prep, base building, race preparation. Filter by duration and difficulty.
Activate the plan
Set your start date and goal event date. The plan will populate your calendar with workouts for each week.
Follow the plan
Each week shows planned workouts. Complete them and log your activities. Track your progress with PMC charts.
Let AI adapt (PRO AI)
If you miss workouts or life gets in the way, Adaptive Planning will suggest adjustments to keep you on track.
Why use it?
- Structured progression: Follow proven periodization principles instead of random training
- Reach goals faster: Properly designed plans help you improve without overtraining
- Save time: No need to plan every workout yourself—follow proven templates
- Build your own: Use the plan builder to create custom multiweek programs
Ready to get started?
Start using TrainCraft's powerful features today. Free tier available, no credit card required.