Strength Index explained
A fitness tracker should answer one question: am I getting stronger? Strength Index is TrackIron’s way of turning your gym log into a chart you can actually read.
What it is
Strength Index is a progress score built from the lifts you log — so upper and lower body trends show up as lines over time, not only as scattered PRs in a notebook.
Why charts beat “feeling stronger”
Week to week, fatigue and sleep muddy intuition. A strength chart from consistent workout logs shows whether your training is stacking — across 1 week, months, or a year view.
What to look at
- Direction — is the line drifting up over months?
- Body split — upper vs lower so one lagging side doesn’t hide in an average
- Scores alongside — strength, stamina, and consistency cues that explain flat weeks
- PRs — spikes that confirm the chart when you hit a personal record
How to make Strength Index useful
- Log main lifts in the same units (TrackIron uses kg).
- Train those lifts often enough that the chart has data — not one max attempt a month.
- Check the graph after a training block, not after every warm-up day.
Not a medical score
Strength Index is a training feedback tool from your logged sets. It isn’t a diagnosis or a substitute for coaching or medical advice.
See Strength Index charts in TrackIron — free fitness tracker and gym log for Android.
