January 29, 2026 · 3 min read

The Biggest Mistakes Amateurs Make Reading Their Own Training Data

Training data doesn't lie, but it's easy to misread. A handful of mistakes repeat so often among amateurs that they're worth knowing by heart — before you draw a conclusion from one ride that the ride doesn't actually support.

Mistake 1: Comparing average power across different rides

200 W average on a flat, steady route and 200 W average on a hilly one with frequent descents are completely different efforts. Average power with no context for terrain and variability is practically useless for comparisons — better to look at Normalized Power (NP) and IF, which better reflect the real cost of the effort.

Mistake 2: Treating estimated VO2max as a lab result

Watches and apps estimate VO2max from an algorithm, not a lab measurement. The value can jump by several points day to day with no real change in form — depending on GPS conditions, heart rate, or even the weather. It's not suited to precisely tracking progress.

Mistake 3: Judging your form from one ride

One weak workout doesn't mean your form has dropped, just as one good one doesn't mean you've peaked. Form shows up in the CTL trend over weeks, not in a single result influenced by that day's sleep, stress or hydration.

Mistake 4: Ignoring heart-rate drift

A rising heart rate at constant power during a ride isn't a coincidence — it's a sign of fatigue or dehydration. Amateurs often look only at the average heart rate for the whole ride, missing how it changed over time. More on this phenomenon in our article on cardiac drift.

Mistake 5: Mixing up trainer power and outdoor measurement

Different power measurement sources (trainer, pedals, hub) can differ from each other by a few per cent. Comparing FTP measured on one device with a result from another, without accounting for that difference, leads to false conclusions about "losing form". Check which power measurement source is worth trusting most.

Mistake 6: Focusing on distance and speed instead of power

On the trainer, distance and speed are essentially arbitrary — they depend on the virtual resistance settings, not on real effort. The only reliable measure of work is power and time spent in a given zone.

How to avoid this

The simplest rule: look at trends, not single numbers, and always ask what a given value actually measures before drawing a conclusion from it. If you're wondering which indicators are even worth tracking day to day, see our article on cycling minimalism.

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