What makes phase.fitness different

The only app that does
periodization & adaptation

Most fitness apps create isolated workouts. phase.fitness generates complete, science-based training programs with phased progression, automatic workload adjustments, and recovery management — the same methods used by elite coaches.

Start Your Program

Built on proven training science

Periodization and adaptation are the cornerstones of modern exercise science. phase.fitness is the first consumer app to apply them automatically.

Periodization

Your training is organized into strategic phases — base building, intensification, peak, and recovery. Each phase has a specific purpose: building volume first, then shifting to intensity, then sharpening for performance.

This is how Olympic athletes and professional coaches structure training. phase.fitness brings this methodology to everyone.

Adaptation

Your program isn't static. After each training block, the AI analyzes your actual performance — RPE feedback, completed volume, strength gains — and adjusts the next phase to match your real progress.

Deload weeks are calculated automatically. Progressive overload is managed per-exercise. No guesswork.

AI-Powered Generation

Intelligent workout creation

The AI understands your goals, equipment, and constraints to generate programs that actually make sense.

Goal-Driven

Preparing for a marathon? Building strength? Losing weight? The AI designs complete programs around your specific objective and timeline.

Equipment-Aware

Only have dumbbells? Bodyweight only? Full gym? The AI generates workouts using only the equipment you have available.

Mixed Programs

Combine strength and cardio in the same program. The AI balances training stress across modalities and schedules recovery intelligently.

Athlete Profile

Import your history from Strava and Hevy. The AI builds a comprehensive profile — sport classification, estimated 1RMs, cardio metrics — and uses it in every generation.

Smarter Context

Your athlete profile is automatically injected into all AI prompts. Program creation, routine refinement, and workload adjustments understand your full training background.

Constraint System

Exclude specific exercises, target certain muscle groups, or set equipment constraints per-routine. Regenerate individual routines without touching the rest of your program.

Recently shipped

We ship fast. Here's what we've built recently.

Cardio Routines

AI now generates structured cardio workouts — running, cycling, swimming, and rowing — with intervals, heart rate zones, and duration targets. Cardio routines appear alongside strength routines in your program, with a dedicated card view and inline editor.

Progressive Workload

Every exercise now has automatic week-over-week progression. Sets, reps, and load adjust based on your actual performance — with RPE-based adjustments for compounds and rep-based progression for isolation work. Deload weeks are calculated automatically. No AI credits used.

Intervals.icu Sync

Push cardio routines to Intervals.icu for Apple Watch execution. Connect your account in Settings, then sync cardio workouts with one click from the program page. Workouts appear in your Intervals.icu calendar with structured intervals and zones.

Wellness Monitoring

Track HRV, resting heart rate, sleep quality, and body weight on your dashboard. Wellness data syncs daily from Intervals.icu and feeds into the AI context — your training load adjusts automatically based on recovery signals.

AI Athlete Profile

February 2026

A new AI-powered analysis of your imported training data from Strava and Hevy. The AI reads your workout history and generates a comprehensive athlete profile — sport classification, training frequency, estimated 1RMs, cardio metrics, and key insights. Available on your dashboard after connecting Strava or Hevy.

The AI Athlete Profile is automatically injected into all AI generation prompts — program creation, routine refinement, and workload adjustments now understand your full training background.

Workload Update Overhaul

Completely redesigned workload adjustment: live spinner during processing, then a detailed result screen showing exactly what changed — per-exercise before/after comparison (sets, load%, RPE) and total working sets delta. Six preset options with percentage inputs and validation. Resilient polling that survives network glitches.

Connected Ecosystem

From AI to your wrist

phase.fitness creates the intelligence. Your favorite apps and devices execute the workouts. Through Intervals.icu, your AI-generated cardio routines reach Garmin, Suunto, COROS, Apple Watch, Wahoo, and Amazfit.

Device connectivity is powered by Intervals.icu — a powerful open training platform that we integrate with, not something we built. Credit where it's due.

phase.fitness
AI Training Intelligence
Strava
Import data
Intervals.icu
Cardio & wellness
Hevy
Strength sync
via Intervals.icu
Apple Watch
via Watchletic
Garmin
Connect
Suunto
Sports
COROS
Training Hub
Wahoo
SYSTM
Amazfit
Zepp

Device sync powered by Intervals.icu — a powerful open training platform that connects to all major sports watches and bike computers.

Ready to train with science?

Join athletes who use real periodization and adaptation — not random workouts.