The swim performance gap between competitive swimmers and triathletes is primarily an efficiency gap, not a fitness gap — and is the most likely explanation for age-group swim plateaus
Interpretation
Toussaint (1990) measured that at equal power output, competitive swimmers achieve ~29% more stroke distance per cycle and ~23% higher velocity than triathletes, with propelling efficiency 62±6% vs 44±4%. The implication for age-group triathlete plateaus: adding more training volume addresses fitness but not the fundamental efficiency gap — the explanation for why triathletes often train hard without meaningfully improving their swim split.
Practical implication
When diagnosing a swim plateau, look at stroke efficiency metrics (distance per stroke, stroke rate at a given pace) before adding volume. The Toussaint data is from 1990 and uses a small, elite sample — treat the specific percentages as indicative of the direction, not precise age-group norms.
Sources
1 source, independently verified.
MSSE 22:409–415, PMID 2381311. At the same power output, competitive swimmers achieved 1.28 m stroke distance vs 0.99 m for triathletes, and 1.11 vs 0.90 m/s speed; propelling efficiency 62±6% vs 44±4%. Establishes that the gap between swim-trained and triathlon-trained athletes is primarily efficiency (how power converts to propulsion), not power output — the evidence base for focusing on stroke mechanics over pure fitness in triathlete swim development.