title: Influence of different breathing frequencies on the severity of inspiratory muscle fatigue induced by high-intensity front crawl swimming.
abstract: The aim of the present study was to assess the influence of 2 different breathing frequencies on the magnitude of inspiratory muscle fatigue after high-intensity front crawl swimming. The influence of different breathing frequencies on postexercise blood lactate ([La]) and heart rate (HR) was also examined. Ten collegiate swimmers performed 2 x 200-m front crawl swims at 90% of race pace with the following breathing frequencies: 1) 1 breath every second stroke (B2), and 2) 1 breath every fourth stroke (B4). Maximal inspiratory pressure (PImax) was measured at the mouth from residual volume before (baseline) and after swimming, in a standing position. The HR and [La] were assessed at rest and immediately at the cessation of swimming. The PImax decreased by 21% after B4 and by 11% after B2 compared with baseline (p < 0.05). The [La] was lower by 15% after B4 than after B2 (p < 0.05). The HR was not significantly different between B2 and B4. These data suggest that there is significant global inspiratory muscle fatigue after high-intensity swimming. Inspiratory muscle fatigue is, however, greater when breathing frequency is reduced during high-intensity front crawl swimming. Respiratory muscle training should be used to improve respiratory muscle strength and endurance in swimmers.
authors.affiliation: Research Centre for Health Studies, Buckinghamshire New University, Chalfont Campus, Chalfont St Giles, United Kingdom. djordje.jakovljevic@bucks.ac.uk
authors.forename: Djordje G
authors.initials: DG
authors.lastname: Jakovljevic
authors.forename: Alison K
authors.initials: AK
authors.lastname: McConnell
mesh_terms: D000704:Analysis of Variance; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007773:Lactates / Q000097:blood; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology; D011187:Posture / Q000502:physiology; D012119:Respiration; D012132:Respiratory Muscles / Q000502:physiology*; D018709:Statistics, Nonparametric; D013550:Swimming / Q000502:physiology*; D055815:Young Adult
chemical_list: D007773:Lactates