Reproducibility of Pacing Strategy during Simulated 20-km Cycling Time Trials in Well-Trained Cyclists
Seventeen well-trained male cyclists rode three 20-km time trials on a Velotron ergometer within 14 days, with power, cadence, gas exchange, RPE, affect and blood lactate recorded.
The pacing strategy was similar across the repeat trials, but more variable at the start and end (typical error 6.6% and 6.8% for the first and last km), with a trend for a progressively blunted start on repeat trials. Performance, cardiorespiratory and perceptual measures were reproducible (TE 1.0-4.0%); blood lactate was not (TE 17.7%).
Participants
n=17 well-trained male cyclists (abstract: "Seventeen well-trained male cyclists"), VO2max 4.70 ± 0.33 L min(-1). Age is not given in the abstract.
Protocol
Three 20-km time trials on a Velotron Pro cycle ergometer within a maximum of 14 days.
Recorded throughout: power output, cadence, respiratory exchange; RPE and affect every 2 km; capillary lactate every 4 km.
Power assigned to 1-km bins and expressed relative to the mean to quantify pacing.
Reproducibility: typical error (TE) with 90% confidence intervals.
Key Results
| Measure | Typical error |
|---|---|
| Performance, cardiorespiratory and perceptual measures | 1.0-4.0% |
| Pacing, first 1 km | 6.6% |
| Pacing, last 1 km | 6.8% |
| Blood lactate | 17.7% |
The pacing strategy was similar across repeat trials, with more variability at the start and end.
Trend for a progressively blunted start on repeat trials.
Practical Application
In seventeen well-trained male cyclists repeating a self-paced 20-km ergometer time trial three times within 14 days, performance and physiological responses varied by only 1.0-4.0% (typical error) and the pacing shape was the same, except in the first and last km (6.6% and 6.8%) and for blood lactate (17.7%). A trained rider's 20-km TT is a reproducible test; a change smaller than a few percent may be noise, and a first-km or final-km difference means little on its own.
Riders tended to start more conservatively each time they repeated the trial; expect a learning effect when a rider rehearses a course or test.
Do not track fitness with lactate from a single TT: its typical error (17.7%) is several times the performance error.
Inference, not tested here: when checking whether a new pacing plan helped, compare the middle of the ride and the total time, not the opening kilometre.
Limitations
Laboratory ergometer; men only; well-trained riders.
Three trials in 14 days; the blunted start suggests a learning effect not fully removed by the third trial.
Written from the abstract and record metadata only (full text not read).
How this entry was checked and changed
Why this level
reliability study, n=17