REF-938 · Chatard et al., 1995 · Medicine & Science in Sports & Exercise, Vol. · Paper · PubMed

Wet suit effect: a comparison between competitive swimmers and triathletes

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

The study examined the wet suit effect in 8 swimmers and 8 triathletes. For the swimmers, 400-m swim performance with and without a wet suit was not statistically different; for the triathletes, swim time was reduced by 19 s. In swimmers VO2max and blood lactate were lower with the suit; in triathletes stroke rate was higher with it.

Across the whole group the individual performance differences were related to the blood lactate differences and to hydrostatic lift. For triathletes the energy cost of swimming and the gliding ability were significantly lower with the suit and decreased with velocity; for swimmers they did not change.

The authors conclude that the wet suit improves performance more in inefficient swimmers with low buoyancy, swimming at low speeds.

Participants

n=16 (8 swimmers and 8 triathletes); MEDLINE indexing lists adolescent and adult participants.

Protocol

400-m swim with and without wet suit in each participant.
VO2max, blood lactate, stroke rate, energy cost of swimming, gliding ability and hydrostatic lift measured.
Individual performance differences related to lactate differences and hydrostatic lift across the whole group.

Key Results

400-m swimWith wet suitWithoutDifference
Swimmers4 min 12.5 +/- 8 s4 min 13.9 +/- 4 snot statistically different
Triathletes4 min 45.8 +/- 34 s5 min 04.7 +/- 30 sreduced by 19 s, P < 0.01
Swimmers: VO2max and blood lactate lower with the wet suit (P < 0.01); energy cost and gliding ability not different.
Triathletes: stroke rate significantly higher with the wet suit (P < 0.01); energy cost of swimming and gliding ability significantly lower, and decreased with velocity.
Whole group: individual performance differences related to blood lactate differences (r = -0.68; P < 0.01) and to hydrostatic lift (r = 0.63; P < 0.01).

Practical Application

Over 400 m, a wet suit cut eight triathletes' swim time by 19 s (4 min 45.8 s vs 5 min 04.7 s) but did not change eight competitive swimmers' time (4 min 12.5 s vs 4 min 13.9 s). To "how much faster will a wetsuit make me?": the weaker and less buoyant the swimmer, the bigger the gain — the authors conclude it helps most "in inefficient swimmers with low buoyancy, swimming at low speeds".
A good pool swimmer should not count on a large time gain from the suit.
Inference, not tested here: the 19 s applies to these triathletes over 400 m; it should not be multiplied out to longer race distances, and an athlete's own gain is best taken from timed swims with and without the suit.
Inference, not tested here: because part of a weak swimmer's wetsuit speed comes from the suit, pool times without it understate race pace in a wetsuit-legal swim and overstate it when wetsuits are banned.
Not from this paper; the base's own practice: rehearse open-water swims in the race wetsuit before race day SYNTH-74; cold-water safety is in REF-654.

Limitations

Eight per group; swimmer and triathlete level, sex and wetsuit model are not in the abstract.
400 m only, 1995 wetsuits; modern suits and longer open-water swims were not tested.
Order of the suit and no-suit trials is not described in the abstract.
Written from the abstract and record metadata only (full text not read).
How this entry was checked and changed
Why this level

within-subject comparison, two groups of 8