FitTrack

The problem

I train in the gym and climb. As a new parent, my training time is short and unpredictable. Generic fitness apps either ignore recovery or hide their logic behind a subscription and a black box.

I wanted one place that answers two questions every morning: how recovered am I? and given the time I have, what should I train? The answer should be explained, so I can decide whether to follow it.

What it does

Workout logging and plans

Log sets, reps and weights against reusable plans. The next session pre-fills from last time, so progression is visible.

Nutrition tracking

Calories and macros against a daily target, with food search through the open Open Food Facts database.

Daily readiness score

Sleep, heart-rate variability, resting heart rate and training load from a Samsung Health export, each compared with my own recent baseline and combined into one score from 0 to 100.

Smart Coach (rule-based)

Suggests the muscle group trained longest ago, drops grip-heavy exercises within 24 hours of a climbing session, and trims accessories when time is short.

Progress charts

Strength, body and activity trends over time.

Try it

Runs entirely in your browser with made-up data. Nothing is sent anywhere.

Readiness and next workout

Move the sliders to set up a made-up morning. The score and the suggestion use the same weights and rules as FitTrack's coach.

This morning

Sleep score78

HRV versus your 60-day baseline+6%

Resting heart rate versus baseline-1 bpm

Training last 7 days (min/day)45

Training last 28 days (min/day)40

Last climbing session

Not in the last 48 h10 hours ago30 hours ago

Time available

30 min45 min60 min

Days since last trained

ChestBackLegsShoulders

Readiness

73/ 100 · Good to push

Good to push. Training load is the strongest signal (load 1.1x baseline, in the productive range).

Sleep (35% weight)78

Score 78

HRV (25% weight)59

+6% vs 60d baseline

Resting HR (20% weight)56

-1 bpm vs baseline

Training load (20% weight)100

Load 1.1x baseline, in the productive range

Suggested session

Pull Day — Back Focus about 45 min

Barbell Row: 4 × 6-8 · rest 120s
Pull-Up: 3 × 6-10 · rest 90s
Seated Cable Row: 3 × 8-10 · rest 90s
Face Pull: 3 × 12-15 · rest 60s
Barbell Curl: 3 × 8-10 · rest 60s
Hammer Curl: 3 × 10-12 · rest 60s

Why: Back is the group trained longest ago.

Architecture

In words

The app is a web app I install on my phone. It talks to a small API on my home server, reached privately over Tailscale.

All data sits in one SQLite database. A Samsung Health export is imported on demand. Re-running the import updates records instead of duplicating them.

The readiness score and the coach are plain functions over that database. The only outside call is the food search.

How I built it

I wrote the requirements from my own routine: limited, unpredictable training time as a new parent, and climbing alongside the gym.

I designed the product and architecture, including how the readiness score should behave. The code was written with Claude Code. I reviewed it, and the readiness scale was calibrated against a year of my own history.

A trade-off I made deliberately. The first design called a paid AI model for coaching. I replaced it with rules: they cost nothing to run, work offline, and every suggestion comes with its reason.