Track four numbers, not forty: FTP every 4–6 weeks, daily TSS, the weekly CTL/TSB trend, and resting HR or HRV. Everything else is detail that matters only once these are consistent.
Fewer metrics, better decisions
Training devices produce dozens of numbers per session; almost none of them change your decisions. Improvement comes from four feedback loops: how strong you are (FTP), how much work you did (TSS), what shape you are in (CTL/TSB), and how recovered you are (resting HR/HRV). Track those, review them weekly, and ignore the rest until they are habitual.
The failure mode is dashboard archaeology — studying pedal smoothness while skipping recovery weeks. A metric earns its place only by changing what you do next.
The metrics that matter, ranked
| Metric | What it tells you | How often to check |
|---|---|---|
| FTP | Your sustainable intensity ceiling (power or pace) — it sets every training zone | Test or estimate every 4–6 weeks |
| Power, HR, or pace zones | Whether each session hits its intended intensity | Every session, while training |
| TSS | Daily training load for planning fatigue | Daily, at a glance |
| CTL / ATL / TSB | Fitness trend, fatigue, and form for timing key sessions | Weekly review |
| IF | How hard a session was relative to your FTP | After hard sessions |
| Resting HR / HRV | Recovery status and overtraining warning | Each morning |
| Weight-to-power (W/kg) | Climbing and overall performance ceiling | Monthly, with a weight trend |
Why each top metric matters
- FTP — the anchor. Every zone, every interval target, and most app plans derive from it; a stale FTP makes every zone target quietly wrong.
- TSS — turns sessions into comparable numbers, so a 90-minute easy session and a 60-minute threshold workout can be planned side by side.
- CTL/TSB — tells you when to push and when key sessions will land: plan breakthrough sessions on positive form, not on a tired trend.
- Resting HR/HRV — your early-warning system; costs two minutes each morning and catches problems power data misses.
Metrics to ignore (for now)
- Pedal smoothness and torque effectiveness — near-maximal on modern trainers, no actionable signal.
- VAM and climbing dynamics — useful for mountain-stage racers, noise for everyone else.
- Real-time FTP estimates on every ride — retest properly instead; estimates drift with fatigue.
- Segment-chasing watts — motivates surges that wreck the Zone 2 distribution the other metrics are measuring.
A 10-minute weekly review that works
Once a week, same day: check the CTL trend (rising 3–7 points per week is sustainable for most amateurs), TSB for the coming week (plan key sessions on positive form), your completed-versus-planned ratio (90%+ is winning), and your morning resting-HR baseline. Four numbers, ten minutes, every week — that is the whole system.
If any metric produces no change in a decision for a month, drop it. Tracking exists to serve training choices, not to become a hobby.
Using Vo2Max
Vo2Max watches the four metrics that matter — FTP, load, form, and your schedule — and lets the generator adjust the plan automatically, so you review one calendar instead of ten dashboards.