REF-792 · Padilla et al., 2000 · Medicine & Science in Sports & Exercise, Vol. · Paper · PubMed

Exercise Intensity During Competition Time Trials in Professional Road Cycling

Blimited evidenceMeasured on world-class athletesWritten before October 2026, being re-checked

Eighteen world-class cyclists did an incremental laboratory test (maximal power, maximal heart rate, OBLA, lactate threshold and a heart-rate/power relationship), then wore heart-rate monitors in 12 prologues (<10 km), 18 short (<40 km), 19 long (>40 km), eight uphill and seven team time trials.

The longer the time trial, the lower the heart rate relative to maximum and to both lactate markers: prologues sat at 100 ± 3% of HR at OBLA, long time trials at 89 ± 5% of HR at OBLA and 103 ± 8% of HR at the lactate threshold. The authors conclude that HR at OBLA marks race intensity in events of up to about 30 min and HR at the lactate threshold in events of 30 min or more.

Participants

n=18 world-class professional road cyclists (abstract: "Eighteen world-class cyclists"). Sex, age and physiological values are not given in the abstract.

Protocol

Incremental laboratory cycling test: maximal power output (Wmax), maximal HR (HRmax), onset of blood lactate accumulation (OBLA), lactate threshold (LT) and an HR-power output relationship.
Zones: OBLA zone = HR(OBLA) ± 3 beats/min; LT zone = HR(LT) ± 3 beats/min.
HR monitored in competition: 12 prologues (PTT, <10 km), 18 short (STT, <40 km), 19 long (LTT, >40 km), eight uphill (UTT) and seven team (TTT) time trials.
Each rider's power in racing was estimated from competition HR through his HR-power relationship; training impulse (TRIMP) was estimated from HR and race duration.

Key Results

Time trial%HRmaxTRIMPHR as % of HR(OBLA)HR as % of HR(LT)
Prologue (<10 km)89 ± 3%21 ± 3100 ± 3%114 ± 8%
Short (<40 km)85 ± 5%77 ± 2395 ± 7%108 ± 9%
Long (>40 km)80 ± 5%122 ± 2789 ± 5%103 ± 8%
Uphill78 ± 3%129 ± 1487 ± 2%101 ± 5%
Team82 ± 2%146 ± 691 ± 4%105 ± 11%
HR(OBLA) was the accurate intensity marker for events lasting up to about 30 min (prologue and short TT); HR(LT) for events of 30 min or more (long, uphill and team TT).
The estimated power outputs are not reported in the abstract.

Practical Application

In 18 world-class professionals, heart rate in long time trials (>40 km) averaged 89 ± 5% of the heart rate at OBLA and 103 ± 8% of the heart rate at the lactate threshold, against 100 ± 3% and 114 ± 8% in prologues (<10 km); the authors conclude that HR at OBLA marks race intensity in time trials of up to about 30 min and HR at the lactate threshold in those of 30 min or more. For a 40 km time trial the answer to "how hard?" is: around your lactate threshold, clearly below the intensity of a short prologue.
Uphill time trials were ridden at the lowest share of HRmax (78 ± 3%) but close to HR at LT (101 ± 5%); read the lactate markers, not %HRmax, when comparing efforts on different terrain.
Inference, not tested here: an amateur is slower than these riders over the same distance, so a 40 km time trial falls even more clearly into the "30 min or more" band where the lactate threshold, not OBLA, is the reference.
Not from this paper; the base's own practice: set the power target from a threshold or critical-power test done in the time-trial position (REF-201) and use heart rate as a cross-check, because heart rate lags at the start and drifts upward over a long effort.
The paper's numbers are heart rate; do not convert them into a watts target from this entry.

Limitations

Intensity is estimated from heart rate through a laboratory HR-power relationship; heart rate drifts and is affected by heat, hydration and position, none of which the abstract reports controlling.
World-class professionals only; sex, age and physiological values are not in the abstract.
The number of time trials each rider contributed and their durations are not given in the abstract.
Written from the abstract and record metadata only (full text not read); the power estimates exist in the paper but not in the abstract.
How this entry was checked and changed
Why this level

cross-sectional field observation, n=18; intensity inferred from heart rate, not measured power