Table 6.
Natural/occupational whole-body cold water immersion.
| Reference | Study Sample | Habituation Length | Habituation Temperature | Cold Testing Procedure | Results/Findings |
|---|---|---|---|---|---|
| Skreslet [149] | 3 M nonprofessional scuba divers | Daily water immersion for 45 days, length of individual dive unknown | Minimum sea temperature of 2.5–3.5°C | Normal sea dives + standard dives in cooled bath to replicate sea temperatures; wearing neoprene suit, gloves, boots | Pattern of acclimatization: 1) unacclimatized: cold stress not met with an ↑ metabolic rate to compensate heat loss, 2) intermediate: ↓ in TC as heat loss is not fully compensated for by metabolism, 3) acclimatized: ↔ TC maintained with minor metabolic heat production |
| Paik [150] | 8 F Korean Ama; 8 F CON | Occupational exposure: 15 min to 2 ½ hrs of full-body exposure year round | 10–27°C, season dependent, in cotton bathing suit | 6°C hand immersion for 30–60 min | Across seasons, Ama maintained ↑ muscle temperature compared to CON; Finger skin temperature and blood flow ↓; ↑ fraction of venous return via superficial veins; Ama did not appear to undergo CIVD fluctuations; Overall, ↑ vasomotor tone |
| Dressendorfer [151] | 12 M athletes; 6 long-distance runners, 6 long-distance swimmers | ~1.5 years (runners averaged ~110 km of road running per week in year-round training; swimmers swam 10 km per week year-round) | Runners: air temperatures of 21–29°C; Swimmers: open water temperatures of 23–25°C |
Cold tolerance test: 2 hr head-out circulating (6.4 m/min) water immersion wearing a swim suit in 30°C | Hypothermic insulative adaption in runners that may be related to a vascular mechanism; during the first 75 min of the CT test, Trec in the runners fell 0.3°C/h faster than in the swimmers despite ↔ in metabolic response, calculated insulation values in the runners were ~10% ↑ than the swimmers attributable to elevated nonfat insulation (at a similar level to Korean Ama); marathon training may provide cross-adaptation to cold |
| Huttunen [152] | 6 M, 1 F Russian Long-distance swimmers | Unknown previous practice exposure; 4 days standard exposure, 2x/day | 10–14°C | Longitudinal passive observation | ↓ rise in diastolic blood pressure on 4th compared to 1st day; Self-determined swimming time lengthened by ~10 min from day 1 to day 4 |