trainOS is an AI-powered training platform for triathletes that syncs your devices, auto-detects your thresholds, models cross-discipline fatigue, and dynamically adjusts your plan — so you peak on race day, not before it.
A complete training system built specifically for multi-sport athletes. Plan, execute, analyze, and adapt — all in one place.
The central hub for planning and reviewing your training. Planned workouts, completed sessions, and unlinked activities — all auto-matched and organized. Weekly statistics, training phase detection, and daily CTL/ATL/TSB projections.
Every workout is analyzed across four physiological domains: aerobic metabolic, aerobic power, anaerobic metabolic, and neuromuscular.
Weeks are automatically classified into training phases based on PMC metrics — base, build, peak, taper, and recovery.
Full-featured structured workout designer for all three disciplines. Drag-and-drop segments, interactive timeline visualization, real-time TSS calculations, and a natural language swim workout parser.
Your at-a-glance training overview. CTL, ATL, TSB tracking with composited time-series charts, weekly TSS breakdown by discipline, and auto-detected training phase badges.
Your performance thresholds are detected automatically from training data — no lab tests needed. Critical Power, Critical Speed, and VO2max estimation with breakthrough and decay detection.
Aggregated weekly metrics with TSS breakdown by discipline, duration totals, and no double-counting between manual and synced data. Spot fatigue spikes, big-volume weeks, and discipline balance at a glance.
A neural network that learns how swim, bike, and run interact in your body — then adjusts your plan so you keep progressing without overtraining.
Training data flows in from every session and device you connect.
The AI models cross-discipline fatigue and detects how each sport affects the others.
Your plan adjusts automatically based on your current fitness, fatigue, and training phase.
Arrive at race day with maximum fitness and minimum fatigue. Every session has a purpose.
Understands how bike volume affects your run, how swim fatigue impacts recovery, and how cumulative stress compounds across all three sports.
Monitors fatigue risk in real-time. When load spikes or recovery drops, the engine scales back your plan before problems surface.
Adjusts differently for base, build, peak, and taper. A fatigued athlete in taper gets a volume cut. In build, they get a smarter redistribution.
trainOS learns your personal baselines across morning HRV, resting heart rate, and aerobic efficiency — then flags when you're drifting into over-training or under-recovery, often days before performance drops.
Normalized power divided by average heart rate over a steady effort. Week-over-week EF is the clearest signal that aerobic fitness is actually improving — more wattage for the same cardiovascular cost.
Morning HRV reflects how well your nervous system cleared yesterday's load. trainOS compares each day to your 60-day baseline — a sustained dip below the band is the earliest warning of accumulating fatigue.
trainOS fuses morning HRV and resting heart rate into a single z-score against your 60-day baseline. Above +1 means your nervous system is adapting and cleared for hard training; a sustained slide below −1 is the earliest flag of overreaching, long before performance drops.
Drop in power-to-heart-rate ratio between the first and second half of a steady session. Under 5% signals strong aerobic durability; higher values reveal where fitness still needs to build.
How much heart rate climbs across a constant effort. 0–10% is normal; higher drift flags accumulating fatigue mid-session — a reason to pull short rather than push through.
See how trainOS compares against the leading endurance training platforms.
14-day free trial with full access to every feature. No credit card required.
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Advanced AI coaching and nutrition.
Everything in Basic, plus: