Three metrics beat thirty charts
Volume = sets × reps × load
The best single proxy for hypertrophy stimulus. Research converges on roughly 10–20 hard sets per muscle per week; more isn't automatically better once recovery slips.
Overload rate
Strength grows when this week asks slightly more than last week — about 1–3% added load or a rep or two. Bigger jumps mostly add injury risk, not muscle.
Estimated 1RM
You never need to max out to track strength. The Epley formula estimates it from any hard set: 1RM ≈ weight × (1 + reps/30).
Worked example
Squat 8 reps at 100 kg → est. 1RM = 100 × (1 + 8/30) ≈ 126.7 kg.
Now run 2.5%/week for 12 weeks with a deload every 4th week (–40% volume). Working weight ends near 131 kg — a 31% overload — while the deloads keep fatigue from compounding. That periodic dip you see in the 3D chart isn't lost progress; it's what lets the next block go up.
Why clean analytics UIs win
A log you'll actually fill in beats a dashboard you admire once. The design lesson from the best trackers: one hero number per screen, trends over absolutes, and a deload that renders as intentional, not as failure. If your app makes the graph above legible in three seconds, it's doing its job.