REF-842 · Kyle, 1979 · Ergonomics, Vol. · Paper

Reduction of Wind Resistance and Power Output of Racing Cyclists and Runners Travelling in Groups

C+thin evidenceMeasured on a mixed groupWritten before October 2026, being re-checked

Abstract source: the publisher's abstract as carried by OpenAlex; the paper has no abstract in PubMed, Europe PMC or Crossref. Wind resistance accounts for most of the metabolic cost of cycling (80–90%) but much less for runners (4–8%). Riders and runners behind others use less energy because they are partly shielded from the wind.

The paper presents experimental data on the reduction of wind resistance and power output in groups: for cyclists, external power output was reduced by over 30% at racing speeds; for runners, energy consumption fell only 2–4% at middle- and long-distance speeds.

A method for predicting the speed of groups is given, and the author calls the pace line by far the most important tactic in cycle racing.

Participants

Not given in the abstract (racing cyclists and runners; number, level and sex not stated).

Protocol

Experimental measurements of group wind resistance and power output for cyclists and for runners travelling in groups.
A method of predicting the speed of groups of cyclists and runners.
Details of the measurement method are not given in the abstract.

Key Results

Share of metabolic cost from wind resistanceSaving when shielded in a group
Cyclists80–90%external power output reduced over 30% at racing speeds
Runners4–8%energy consumption decreased only 2–4% at middle and long distance speeds
Travelling in a group raises the speed cyclists can hold far more than it does for runners; the speed-gain figures are garbled in the digitised abstract and are not cited here.
Author's conclusion: the use of pace lines in cycle racing is by far the most important race tactic; in running, systematic use of pacing is not yet fully used although the benefits are potentially significant.

Practical Application

How much does sitting on a wheel save? In this early measurement study, a cyclist shielded in a group needed over 30% less external power at racing speeds, whereas a runner behind others saved only 2–4% of energy, because wind resistance is 80–90% of the cost of cycling but only 4–8% of the cost of running. In a road race or criterium, time out of the wind is the largest free saving available; spend it deliberately and pull only when it serves the plan.
For runners the saving is real but small; running behind a pacer helps, but position matters far less than it does on a bike.
Inference, not tested here: the saving depends on speed, gap and position in the group, and modern bikes, clothing and bunch formations differ from those measured then; treat "over 30%" as the order of magnitude, not a number for a given wheel.
Not from this paper; the base's own practice: in draft-legal triathlon, holding a wheel continuously rather than sharing the lead lowered bike VO2, heart rate and lactate and gave a faster run (REF-657); in non-drafting age-group triathlon this saving is not available (REF-538).

Limitations

Measurements from the late seventies; equipment, positions and bunch dynamics have changed.
Sample size, participant level and measurement method are not given in the abstract.
Not indexed in PubMed or Europe PMC; the abstract comes from the publisher record via OpenAlex, and part of it (the speed gains) is garbled in digitisation.
Written from the abstract and record metadata only (full text not read).
How this entry was checked and changed
Why this level

early mechanistic measurement study, no sample size in the abstract, abstract from the publisher record only