REF-939 · Chatard & Wilson, 2003 · Medicine & Science in Sports & Exercise, Vol. · Paper · PubMed

Drafting Distance in Swimming

Blimited evidenceMeasured on a mixed groupWritten before October 2026, being re-checked

The study tested how far a drafting swimmer sits behind the leader affects the follower's metabolic and hydrodynamic responses. 11 swimmers did a 4-min swim at 95% of their best 1500-m pace without drafting, and again drafting straight behind another swimmer at four gaps (0, 50, 100, and 150 cm).

In every drafting position oxygen uptake, heart rate, blood lactate, perceived exertion and stroke rate fell significantly, and stroke length rose significantly. Passive drag was lowest with the follower 0 or 50 cm behind the leader's toes, cut by 21% and 20% respectively.

Swimming to the side (lateral drafting), drag fell by 6% and 7% with the follower 50 and 100 cm behind the leader's hands.

Participants

11 swimmers for the swimming trials; six swimmers for the lateral passive-drag measurements. MEDLINE indexing lists adult participants.

Protocol

Nondrafting swim: 4 min at 95% of the best 1500-m pace; compared with drafting directly behind another swimmer at 0, 50, 100, and 150 cm.
Measures: stroke rate, stroke length, oxygen uptake, heart rate, blood lactate, rating of perceived exertion (Borg scale).
Passive drag by passive towing at the same drafting distances.
Lateral drafting: six swimmers were towed at six positions beside the lead swimmer, with about 40 cm between the two swimmers, to measure passive drag; then at two positions behind the lead swimmer, with the sideways gap cut to 50 and 0 cm.

Key Results

All drafting positions vs nondrafting: lower stroke rate, rating of perceived exertion, blood lactate, heart rate and oxygen uptake (all significant); longer stroke length (significant).
Behind the lead swimmer: the most advantageous distances were 0 and 50 cm back from the toes; drag reduced by 21% and 20%, respectively.
Lateral drafting: with the follower 50 and 100 cm behind the leader's hands, drag fell significantly, by 6% and 7%.

Practical Application

In 11 swimmers swimming 4 min at 95% of their best 1500-m pace, drafting directly behind another swimmer lowered oxygen uptake, heart rate, lactate and perceived exertion at every distance tested (0 to 150 cm); passive drag was cut most — by 21% and 20% — at 0 and 50 cm behind the leader's toes. To "where should I sit in the swim?": on the feet, within about half a metre of the toes.
If the feet are not available, swim alongside: lateral drafting 50-100 cm back from the leader's hands cut drag by 6% and 7% — a smaller but real saving.
Stroke rate fell and stroke length rose when drafting: the same speed with a longer, slower stroke.
Inference, not tested here: in a triathlon the saved effort can be spent on the bike and run; the swim-intensity crossover REF-940 shows a below-time-trial swim improving the rest of a sprint triathlon.
Not from this paper; the base's own practice: practise close-contact swimming and sighting in open water before racing in a pack SYNTH-74.

Limitations

n=11 (six for lateral drag); level and sex are not in the abstract.
Drag reductions are from passive towing, not active swimming; the metabolic savings are reported as significant without magnitudes in the abstract.
Controlled conditions, one lead swimmer, 4-min swims; no open water, waves, pack dynamics or wetsuits.
Written from the abstract and record metadata only (full text not read).
How this entry was checked and changed
Why this level

within-subject crossover, n=11 (lateral-drag part: six swimmers)

Content correction 2026-09-27
2026-10-01: independent check against the abstract — wording brought back to what the abstract states.