title: Crushed Ice Ingestion Does Not Improve Female Cycling Time Trial Performance in the Heat.
abstract: This study examined the effects of precooling via ice ingestion on female cycling performance in hot, humid conditions. Ten female endurance athletes, mean age (28 ± 6 y), height (167.6 ± 6.5 cm) and body-mass (68.0 ± 11.5 kg) participated in the study. Participants completed an 800 kJ cycle time-trial in hot, humid conditions (34.9 ± 0.3 °C, 49.8 ± 3.5% RH). This was preceded by the consumption of 7 g∙kg-1of crushed ice (ICE) or water (CON). There was no difference in performance time (CON 3851 ± 449 s; ICE 3767 ± 465 s), oxygen consumption (CON 41.6 ± 7.0 ml∙kg∙min-1; ICE 42.4 ± 6.0 ml∙kg∙min-1) or respiratory exchange ratio (CON 0.88 ± 0.05; ICE 0.90 ± 0.06) between conditions (p > .05, d < 0.5). Core and skin temperature following the precooling period were lower in ICE (Tc36.4 ± 0.4 °C; Tsk31.6 ± 1.2 °C) compared with CON (Tc37.1 ± 0.4 °C; Tsk32.4 ± 0.7 °C) and remained lower until the 100 kJ mark of the cycle time-trial (p < .05, d > 1.0). Sweat onset occurred earlier in CON (228 ± 113 s) compared with ICE (411 ± 156 s) (p < .05, d = 1.63). Mean thermal sensation (CON 1.8 ± 2.0; ICE 1.2 ± 2.5, p < .05, d = 2.51), perceived exertion (CON 15.3 ± 2.9; ICE 14.9 ± 3.0, p < .05, d = 0.38) and perceived thirst (CON 5.6 ± 2.2; ICE 4.6 ± 2.4, p < .05, d = 0.98) were lower in ICE compared with CON. Crushed ice ingestion did not improve cycling performance in females, although perceptual responses were reduced.
authors.forename: Matthew
authors.initials: M
authors.lastname: Zimmermann
authors.forename: Grant Justin
authors.initials: GJ
authors.lastname: Landers
authors.forename: Karen Elizabeth
authors.initials: KE
authors.lastname: Wallman
mesh_terms: D000328:Adult; D056352:Athletes; D054874:Athletic Performance; D001642:Bicycling; D015992:Body Mass Index; D004305:Dose-Response Relationship, Drug; D005260:Female; D006339:Heart Rate; D006358:Hot Temperature; D006801:Humans; D007053:Ice; D010101:Oxygen Consumption; D010807:Physical Endurance; D005082:Physical Exertion; D012881:Skin Temperature; D013546:Sweating; D013697:Thermosensing; D013894:Thirst; D055815:Young Adult
chemical_list: D007053:Ice
keywords: core temperature; ice slushy; pre-cooling; sweat rate