The Effects of Palmar Cooling on Repeated Sprinting Ability: A Randomized Controlled Clinical Trial
Participants
n=15 graduate students (8 male, 7 female; average age 24.06 yr), randomly assigned to palmar cooling or placebo
Protocol
10-min warm-up, then ten 60-m sprints each including two 180-degree changes of direction
Three 2-min bouts of palmar cooling (intervention) or placebo during the session
Sprint times, heart rate and RPE throughout; muscle-soreness rating by survey 48 h after
Key Findings
Palmar cooling group: less degradation in sprint times across the repeated sprints
Palmar cooling group: lower heart rate upon completion
Palmar cooling group: lower soreness rating 48 h after testing
The authors report statistically and practically significant between-group differences for average sprint times, heart rate and delayed-onset muscle soreness (no effect sizes or values in the abstract)
Proposed mechanism (background, not measured here): arteriovenous anastomoses in the palms allow heat to be pulled from the returning blood — inference, not tested in this trial (core temperature was not reported in the abstract)
Limitations
Small sample (n=15, two groups of ~7-8) — the authors call for a larger sample before generalising
Parallel groups, so between-subject variability is not controlled; no values, only significance, in the abstract
Repeated 60-m running sprints, not an endurance or cycling protocol; laboratory-type setting
Practical Application for Cycling
In 15 graduate students randomised to palmar cooling or placebo during ten 60-m sprints with direction changes, three 2-min bouts of palmar cooling reduced the fall-off in sprint times, lowered heart rate at the finish and lowered soreness 48 h later (between-group differences reported as statistically and practically significant; no magnitudes in the abstract). A cheap, logistics-free cooling tool during rest intervals — the evidence here is a small running-sprint trial, so treat transfer to cycling as plausible, not shown.
Inference, not tested: holding a cold bottle or ice in the palms between hard intervals or at feed stops in hot races may blunt heat build-up; the trial used 2-min bouts, which is a sensible minimum to copy.
How this entry was checked and changed
Why this level
regraded 2026-09-27 from B+: parallel RCT, n=15 (rubric: parallel RCT <20)
Content correction 2026-09-27
Level B+ -> B (parallel RCT n=15). Tier "mixed (review/meta)" -> Tier 1: graduate students, no training status. Sport line "cycling, team-sport, sprint" -> "running" (60-m running sprints).
AVA mechanism -> labelled as background/inference (not measured); "1-2 min" -> the trial used 2-min bouts; "extend work capacity before thermal limit" -> not tested; relabelled inference.