Acute anxiety increases the magnitude of the cold shock response before and after habituation.
Cold immersion evokes the life-threatening cold shock response (CSR). We hypothesised that anxiety may increase the magnitude of (Study 1), and diminish habituation to (Study 2), the CSR. Study 1: eleven participants completed two 7-min immersions in cold water (15 °C). On one occasion, to induce anxiety, participants were instructed that the water would be 5 °C colder (ANX); it was unchanged. The other immersion was a control (CON). Study 2: ten different participants completed seven, 7-min immersions. Immersions 1-5 induced habituation. Immersions 6 and 7 were counter-balanced to produce anxiety (ANX) or acted as a control (CON). Anxiety (20 cm scale) and cardiorespiratory responses (cardiac frequency [f(c)]), respiratory frequency [f(R)], tidal volume [V(T)], minute ventilation [V(E)]) were measured in both studies. Results of study 1: participants were more anxious in the ANX immersion (mean [SD]; CON 5.3 [3.6] and ANX 8.4 [5.0] cm). f(c) peaked at higher levels in ANX (136.4 [15.0]; CON: 124.0 [17.6] b min(-1)) and was higher pre-immersion and in minutes 3 and 5-7 by 7.2 [2.1] b min(-1). ANX [Formula: see text] was higher pre immersion and in minutes 5-6. Results of study 2: repeated immersion habituated the CSR. Anxiety was greater prior to ANX (CON 1.9 [2.3], ANX 6.6 [4.8] cm). f (c) in ANX was higher prior to immersion and in minutes 1-2, 4-6 cf CON; ANX f (c) was not different to the CSR seen in pre-habituation. f (R) was higher in minute 1 of immersion 1 (cf min 1 CON and ANX) following which it exceeded the CSR in CON. The magnitude and duration of CSR (f(c), V(E)) increased with anxiety. Anxiety diminishes CSR habituation.
Department of Sport and Exercise Science, University of Portsmouth, Spinnaker Building, Cambridge Rd, Portsmouth, UK. martin.barwood@port.ac.uk
Martin James
MJ
Barwood
Jo
J
Corbett
Richard
R
Green
Tim
T
Smith
Perry
P
Tomlin
Lydia
L
Weir-Blankenstein
Michael J
MJ
Tipton
D000208:Acute Disease; D000328:Adult; D001007:Anxiety / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology; D058639:Cold-Shock Response / Q000502:physiology*; D018592:Cross-Over Studies; D005260:Female; D006185:Habituation, Psychophysiologic / Q000502:physiology*; D006801:Humans; D007101:Immersion; D008297:Male; D012720:Severity of Illness Index; D013997:Time Factors; D055815:Young Adult