REF-541 · Sandbakk, Holmberg, Leirdal & Ettema, 2010 · European Journal of Applied Physiology, Vol. · Paper
Gross Efficiency Distinguishes World-Class from National-Level Sprint Skiers
Protocol & Participants
n=16 male sprint cross-country skiers: 8 world class (WC) + 8 national level (NL); performance level defined by FIS points
Three 5-min stages of treadmill roller skiing in the G3 skating technique at moderate and high work rates
Gross efficiency (GE) = work rate / metabolic rate (MR); work rate = power against gravity + rolling friction; MR from gas exchange and blood lactate
Also measured: cycle length and cycle rate (video), time to exhaustion (TTE), VO2peak, maximal treadmill speed (Vmax), maximal strength
Key Results
WC skiers did NOT differ from NL skiers in aerobic metabolic rate, but showed LOWER anaerobic metabolic rate and HIGHER gross efficiency at a given speed (all p < 0.05)
WC skiers skated with longer cycle length and had higher Vmax and longer TTE (all p < 0.05)
Authors' conclusion: WC skiers are more efficient than NL skiers, proposed to be due to better technique and technique-specific power
Practical Application
In 8 world-class vs 8 national-level male sprint skiers roller-skiing G3 on a treadmill, the world-class group had the same aerobic metabolic rate but lower anaerobic energy use and higher gross efficiency at a given speed (p < 0.05), with longer cycles, higher maximal speed and longer time to exhaustion — at the top, efficiency (technique) rather than the aerobic engine separated the levels
Masters skier: work on technique/efficiency (cycle length at a given speed is the observable), not only on the engine — the world-class advantage was in efficiency, not aerobic rate
Technical progress = "free" speed at the same metabolic cost
Consistent with the McKay logic (REF-529): at higher tiers small aerobic differences → the focus shifts to efficiency. Inference from a cross-sectional comparison
Limitations
Cross-sectional: association of level with efficiency, not proof that training efficiency raises level
Sprint-specific (G3 skating at high work rates); distance races may differ
n=16, males only
How this entry was checked and changed
Why this level
regraded 2026-09-27 from A: cross-sectional comparison of two groups, n=16
Content correction 2026-09-27
Added n=16 (8 WC + 8 NL), the protocol and the abstract's results (same aerobic MR, lower anaerobic MR, higher GE, longer cycle length, higher Vmax/TTE)
"At the SAME high power" -> abstract: "at a given speed"
Level A -> B (cross-sectional, n=16); Sport line "swimming, xc-skiing, sprint" -> "xc-skiing"
Cross-reference descriptions checked against the cited entries' current content; wrong years, wrong entries and claims the cited entry does not make were corrected.