Cover illustration for Connecting wearable data to lifting logs in ten days

What the AI found

“Your HRV drops 18% only when heavy deadlifts follow poor sleep, but remains stable if volume drops by just two working sets.”

Before

Two years of Oura charts never cross-referenced

After

One ten-minute Sunday log that predicted fatigue

The same system, three states — real screens, not a screenshot

1Starting
Apple Notes
  • Oct 12 — Legs felt heavy. Missed final set at 180kg.
  • Oct 19 — Slept 6h15m. Oura said readiness 64. Still pulled.
  • Nov 02 — Wrecked for three days after deadlifts.
  • Nov 14 — Rest day didn't help. Heart rate up all night.
2Working
Claude

Prompt

Here are the last 90 days of my Oura sleep CSV merged with my lifting log from Apple Notes. Identify the specific variable that precedes my lowest 5 HRV recovery days.

Here are the last 90 days of my Oura sleep CSV merged with my lifting log from Apple Notes. Identify the specific variable that precedes my lowest 5 HRV recovery days.

AI

Your three worst recovery dips do not correlate with total weekly tonnage. Instead, your HRV drops 18% only when heavy deadlifts follow poor sleep, but remains stable if volume drops by just two working sets.
3Implemented
Google Sheets
Weekly readiness average82/100
Volume adjustment triggered-2 sets Tuesday
Predicted HRV baseline64 ms (actual: 62 ms)
Individual10-Day Challenge in use

Connecting wearable data to lifting logs in ten days

How a powerlifter linked two years of wearable data to his lifting journal in fifteen minutes a day.

A 38-year-old software architect and powerlifter, EU

Tools used

The real tools used here — swap any for your own equivalent. Each links to how we’d set it up.

4 min readWellness & AI editorial
1

Before anything was set up

Two years of Oura ring scores sat isolated in a smartphone drawer while eight notebooks of barbell percentages gathered dust on his desk. He felt chronically flat every third Thursday, assuming it was age or cumulative workload. His wearable gave him a single morning score between 1 and 100, but offered no clue how Tuesday's deadlifts interacted with Saturday's broken sleep. He was tracking everything and understanding almost nothing.

Apple Notes
  • Oct 12 — Legs felt heavy. Missed final set at 180kg.
  • Oct 19 — Slept 6h15m. Oura said readiness 64. Still pulled.
  • Nov 02 — Wrecked for three days after deadlifts.
  • Nov 14 — Rest day didn't help. Heart rate up all night.
2

10-Day Challenge, doing its job

On Day 4 of the 10-Day Challenge, he exported his raw CSV from Oura and pasted ninety days of workout notes into Claude. Instead of asking for generic fitness tips, he used the challenge's structured correlation prompt. Within seconds, the model cut through the noise of bedtime consistency and caffeine logs to pinpoint the exact compound movement and sleep threshold driving his mid-week exhaustion.

Claude

Prompt

Here are the last 90 days of my Oura sleep CSV merged with my lifting log from Apple Notes. Identify the specific variable that precedes my lowest 5 HRV recovery days.

Here are the last 90 days of my Oura sleep CSV merged with my lifting log from Apple Notes. Identify the specific variable that precedes my lowest 5 HRV recovery days.

AI

Your three worst recovery dips do not correlate with total weekly tonnage. Instead, your HRV drops 18% only when heavy deadlifts follow poor sleep, but remains stable if volume drops by just two working sets.
3

The finished system, running on its own

By day ten, the system took eight minutes on Sunday evening. He dumped his raw export from Oura and his session notes from Apple Notes into Claude using a template generated during the challenge. The model flagged next week's recovery liabilities before he packed his gym bag. He no longer woke up guessing whether his legs would hold up under the barbell; the numbers showed him exactly when to pull back.

Google Sheets
Weekly readiness average82/100
Volume adjustment triggered-2 sets Tuesday
Predicted HRV baseline64 ms (actual: 62 ms)
Weekly review time8 minutes

8 minutes

Sunday review time

0 in 6 weeks

Missed lift sessions

Down 40%

Subjective morning fatigue

Ourabiometric capture

Exports clean CSV data for sleep stages, resting heart rate, and nightly HRV.

Claudecross-variable synthesis

Large context window handles months of raw biometric tables alongside freeform text.

Apple Notestraining log capture

Low-friction text capture of lifting sets and subjective fatigue between sessions.

These are the tools used in this story. Any can be swapped for an equivalent you already trust.

Start the 10-Day Challenge

This story runs on 10-Day Challenge. The tools and prompts above are the real build — swap any tool for your own equivalent and follow the same steps.

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