Arm insulation and swimming in cold water

Abstract

To test whether adding insulation to the arms would improve cold water swimming performance by delaying swimming failure (SF). Novice (n = 7) and expert (n = 8) swimmers, clothed and equipped with a personal flotation device, each performed two trials in a swimming flume filled with 10°C water. During free swimming (FS), subjects performed swimming until failure, followed by the Heat Escape Lessening Posture. In free swimming with additional insulation (FSA), subjects wore custom-fitted armbands. Trials ended when rectal temperature decreased to 34°C or after 2 h of immersion. Measurements included: rectal and skin temperatures, heat flow, and various appraisals of swimming performance. FSA was thermally advantageous versus FS. Rectal temperature cooling rates during swimming (dT/dt Swim) were faster for FS compared to FSA (0.050 ± 0.007°C min⁻¹ vs. 0.042 ± 0.006°C min⁻¹, P < 0.01). Armbands maintained arm skin temperature about 10°C warmer, for approximately 70 min (P < 0.001). Although additional insulation did not greatly improve physical performances, video analysis showed that swimming technique in FSA was maintained 10–15% better than in FS between minutes 30 and 50 (P < 0.001). SF was achieved in 5/30 trials, with increases in stroke rate (6.6 str min⁻¹) and decreases in stroke length (0.24 m str⁻¹) observed. In this simulation of cold water swimming survival, equipping subjects with neoprene armbands appears to have partially preserved muscle function, but with unimpressive effects on overall performance. SF is a complex entity, but is evidently related to both triceps skinfold and arm girth.