title: The influence of pre-warming on the physiological responses to prolonged intermittent exercise.
abstract: To examine the influence of pre-warming on the physiological responses to prolonged intermittent exercise in ambient temperatures of 21.5 +/- 0.6 degrees C and relative humidities of 35.7 +/- 5.4% (mean +/- s), six healthy men performed intermittent treadmill running (30-s bouts at 90% of maximal oxygen uptake separated by 30-s static recovery periods) to exhaustion after active pre-warming, passive pre-warming and pre-exercise rest (control). Exercise time to exhaustion was significantly different between all conditions (active, 51.8 +/- 7.2 min; passive, 38.5 +/- 11.1 min; control, 72.0 +/- 17.2 min; P < 0.05). These changes in performance time were closely associated with a significant decline in both the rate of heat storage and heat storage capacity (P < 0.05). Rectal temperature, heart rate and ratings of perceived exertion were significantly higher during exercise in the two pre-warming conditions than in the control condition (P < 0.05). Ratings of perceived exertion were also significantly higher during exercise following passive pre-warming compared with active pre-warming (P < 0.05). During exercise there were no significant differences in serum prolactin, plasma norepinephrine and plasma free fatty acid concentrations between conditions. We conclude that both active and passive pre-warming promote a reduction in prolonged intermittent exercise capacity in environmental temperatures of 21 degrees C compared with pre-exercise rest. These performance decrements were dependent upon the mode of pre-warming and closely reflected alterations in body heat content.
authors.affiliation: Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK. gregson@livjm.ac.uk
authors.forename: W A
authors.initials: WA
authors.lastname: Gregson
authors.forename: A
authors.initials: A
authors.lastname: Batterham
authors.forename: B
authors.initials: B
authors.lastname: Drust
authors.forename: N T
authors.initials: NT
authors.lastname: Cable
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D001831:Body Temperature / Q000502:physiology; D005080:Exercise Test; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006813:Humidity; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010806:Physical Education and Training / Q000379:methods*; D010807:Physical Endurance / Q000502:physiology; D012420:Running / Q000502:physiology*; D013696:Temperature
chemical_list: D001786:Blood Glucose; D019344:Lactic Acid