REF-933 · Toussaint, 1990 · Medicine & Science in Sports & Exercise, Vol. · Paper · PubMed

Differences in propelling efficiency between competitive and triathlon swimmers

Blimited evidenceMeasured on highly trained athletesWritten before October 2026, being re-checked

Two highly trained groups, competitive swimmers and triathletes, were compared to evaluate propelling efficiency as a performance-determining factor in swimming. Using regression equations the groups were compared at an equal power input (1000 W).

They did not differ in gross efficiency, stroke frequency or work per stroke, but the competitive swimmers travelled further per stroke and swam faster, because they used a much higher proportion of their power output to overcome drag and spent less power moving water backwards.

Propelling efficiency (power used to overcome drag / total power output) was 61 +/- 6% in the competitive swimmers and 44 +/- 3% in the triathletes. The author concludes that triathletes should focus on swimming technique rather than on their ability to do work.

Participants

Competitive swimmers (N = 6) and triathletes (N = 5), both described as highly trained; MEDLINE indexing lists male participants.

Protocol

Groups compared, via regression equations, at equal power input (1000 W).
Measures: gross efficiency, stroke frequency, work per stroke, distance per stroke, mean swimming velocity, power used to overcome drag, power expended in moving water backwards.
Propelling efficiency = power used to overcome drag / total power output.

Key Results

At equal power input (1000 W)Competitive swimmersTriathletes
Distance per stroke1.23 m0.92 m
Mean swimming velocity1.17 m.s-10.95 m.s-1
Power used to overcome drag49 W35 W
Power expended moving water backwards32 W45 W
Propelling efficiency (mean +/- SD)61 +/- 6%44 +/- 3%
No group difference in gross efficiency, stroke frequency or work per stroke.

Practical Application

At the same power input (1000 W), six competitive swimmers swam 1.17 m/s and five highly trained triathletes 0.95 m/s; the whole difference lay in how the power was used — propelling efficiency 61% vs 44%, distance per stroke 1.23 m vs 0.92 m — not in gross efficiency, stroke frequency or work per stroke. To "should a triathlete swim more or swim better?": this study's own conclusion is to focus on technique rather than on the ability to do work.
Track distance per stroke: the author proposes it as "a simple criterion to evaluate the improvement in skill"; the better swimmer shows a greater distance per stroke rather than a higher stroke frequency.
Inference, not tested here: fitness from the bike or the run cannot be expected to raise swim speed much while propelling efficiency is low, because the triathletes here already matched the swimmers' work per stroke.
Not from this paper; the base's own practice: the swim framework SYNTH-74 puts technique work before the main set for this reason.

Limitations

Very small groups (N = 6 and N = 5), male, compared once: a group contrast, not an intervention.
Values are derived from regression equations at a fixed power input, not from races.
Triathletes of 1990; the swimming background of today's triathletes may differ.
Written from the abstract and record metadata only (full text not read).
How this entry was checked and changed
Why this level

cross-sectional comparison of two small groups (N = 6 and N = 5)