title: Is V̇O2suppressed during nonapnoeic facial submersion?
abstract: The mammalian dive response (DR) is described as oxygen-conserving based on measures of bradycardia, peripheral vasoconstriction, and decreased ventilation (V̇E). Using a model of simulated diving, this study examined the effect of nonapnoeic facial submersions (NAFS) on oxygen consumption (V̇O2). 19 participants performed four 2-min NAFS with 8 min of rest between each. Two submersions were performed in 5 °C water, 2 in 25 °C water. Heart rate (HR) was collected using chest strap monitors. A tube connected to the inspired port of a non-rebreathing valve allowed participants to breathe during facial submersion. Expired air was directed to a metabolic cart to determine V̇O2and V̇E. Baseline (BL) HR, V̇O2, and V̇Evalues were determined by the average during the 2 min prior to facial submersion; cold shock response (CSR) values were the maximum during the first 30 s of facial submersion; and NAFS values were the minimum during the last 90 s of facial submersion. A 2-way repeated-measures ANOVA indicated that both HR and V̇Ewere greater during the CSR (92.5 ± 3.6 beats/min, 16.3 ± 0.8 L/min) compared with BL (78.9 ± 3.2 beats/min, 8.7 ± 0.4 L/min), while both were decreased from BL during the NAFS (60.0 ± 4.0 beats/min, 6.0 ± 0.4 L/min) (all, p < 0.05). HRCSRwas higher and HRNAFSlower in 5 °C versus 25 °C water (p < 0.05), while V̇Ewas greater in 5 °C conditions (p < 0.05). V̇O2exceeded BL during the CSR and decreased below BL during the NAFS (BL: 5.3 ± 0.1, CSR: 9.8 ± 0.4, NAFS: 3.1 ± 0.2 mL·kg-1·min-1, p < 0.05). The data illustrate that NAFS alone contributes to the oxygen conservation associated with the human DR.
authors: Department of Human Physiology, Gonzaga University, 502 E Boone Ave., Spokane, WA 99258, USA.|Department of Human Physiology, Gonzaga University, 502 E Boone Ave., Spokane, WA 99258, USA.
authors: Sarah
authors: S
authors: Anderson
authors: Department of Human Physiology, Gonzaga University, 502 E Boone Ave., Spokane, WA 99258, USA.|Department of Human Physiology, Gonzaga University, 502 E Boone Ave., Spokane, WA 99258, USA.
authors: Maggie R
authors: MR
authors: Chamberlain
authors: Department of Human Physiology, Gonzaga University, 502 E Boone Ave., Spokane, WA 99258, USA.|Department of Human Physiology, Gonzaga University, 502 E Boone Ave., Spokane, WA 99258, USA.
authors: Samantha
authors: S
authors: Musgrove
authors: Department of Human Physiology, Gonzaga University, 502 E Boone Ave., Spokane, WA 99258, USA.|Department of Human Physiology, Gonzaga University, 502 E Boone Ave., Spokane, WA 99258, USA.
authors: Antonia
authors: A
authors: Partusch
authors: Department of Human Physiology, Gonzaga University, 502 E Boone Ave., Spokane, WA 99258, USA.|Department of Human Physiology, Gonzaga University, 502 E Boone Ave., Spokane, WA 99258, USA.
authors: Keagan R J
authors: KR
authors: Tice
authors: Department of Human Physiology, Gonzaga University, 502 E Boone Ave., Spokane, WA 99258, USA.|Department of Human Physiology, Gonzaga University, 502 E Boone Ave., Spokane, WA 99258, USA.
authors: David B
authors: DB
authors: Thorp
mesh_terms: D000328:Adult; D003080:Cold Temperature / Q000009:adverse effects; D065508:Diving Reflex; D015536:Down-Regulation; D005145:Face; D005260:Female; D006339:Heart Rate; D006801:Humans; D007101:Immersion; D008297:Male; D008954:Models, Biological; D018670:Monitoring, Ambulatory; D010101:Oxygen Consumption; D012123:Pulmonary Ventilation; D013997:Time Factors; D055815:Young Adult
keywords: choc hypothermique; cold shock response; consommation d’oxygène; dive response; facial submersion; oxygen consumption; réponse à la plongée; submersion faciale