REF-490 · Atkinson, Davison, Jeukendrup & Passfield, 2003 · Journal of Sports Sciences, · Paper · PubMed
Science and cycling: current knowledge and future directions for research
Key Findings
Scope: identifies the human and environmental factors that set cycling power output and velocity, links them in a schematic model, and sets research directions for different disciplines, environments and riders.
Physiology: most successful cyclists, whatever the discipline, combine a high maximal aerobic power from an incremental test with the ability to hold relatively high power for long periods; the link to capillarisation and fibre type is complicated by individual cadence choice. The authors call for more research on high-class professionals.
Resistive forces: mathematical modelling and bike-mounted strain gauges (direct power measurement in races) are starting to separate the contributions of air resistance, rolling resistance and gravity. The abstract gives no coefficients, exponents or gradient cut-offs.
Position vs power: interventions on rider position to optimise aerodynamics should also consider their effect on the rider's power output.
Pacing (the abstract's most concrete guidance): an even distribution of power is both physiologically and biophysically optimal for longer time trials (>4 km) in constant wind and gradient; for a 1 km time trial an all-out start is advised; on road time trials the biophysical optimum may be to raise power in headwinds and uphill and lower it in tailwinds and downhill — how much time that saves, and how much variability a rider tolerates, needed more research.
Neglected areas: all-terrain (mountain-bike) racing power outputs and equipment modelling; interactions between dietary factors (pre-race × in-race); the thermal environment as a mediator of fuelling vs fluid replacement; nutrition across repeated stage-race days.
Practical Application
Atkinson et al. 2003 (narrative review): successful cyclists pair high maximal aerobic power with the ability to hold high power for long; even pacing is optimal for time trials over 4 km in steady conditions, an all-out start for 1 km, and on real roads power should go up into headwinds and climbs and down with tailwinds and descents. Use it as the map of what sets speed on a bike — physiology, three resistive forces, pacing, nutrition, heat — not as a source for a specific number.
Not from this paper; the base's own practice: rank equipment and position investments by terrain — aero position and kit for flat time trials, total system mass for long climbs, tyre choice and pressure on rough surfaces — and check any aero change against the power the rider can still produce in that position (the last point is the review's own caution).
Inference, not tested: the "even pacing, but modulate for wind and gradient" advice is what a power-based pacing plan implements; the review itself flagged the time saved as unquantified in 2003.
Limitations
2003 — narrative review; some equipment claims have been refined or superseded (notably tyre and wheel technology since the 2010s)
Does not cover the post-2010 aero-bike + disc-brake + tubeless-tyre era
The abstract gives no quantitative model parameters; the physics detail in the full text was not checked here
How this entry was checked and changed
Why this level
regraded 2026-09-27 from B: narrative review without systematic method, from a leading cycling-science group (Atkinson, Davison, Jeukendrup, Passfield); B is not a rubric grade for a review
Content correction 2026-09-27
Level B -> B+ (a review has no "B" under the rubric; graded as an authoritative narrative review). Sport line "cycling, running, strength" -> cycling.
Removed "aero dominates at racing speeds (v², v³)" formula and "gravity dominates above ~4-5%": not in the abstract. Rewrote Key Findings to the abstract's actual scope: physiology of successful cyclists, resistive-force modelling with strain gauges, position-vs-power caution, pacing (>4 km even; 1 km all-out; modulate for wind/gradient), neglected ATB/nutrition/heat topics.
Discipline-specific equipment ranking relabelled as the base's own practice.