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Influence of fitness on core temperature thresholds for exercise ventilation (882.6)
Author(s) -
Yogev Assaf,
Martin Des,
Walsh Michael,
White Matthew
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.882.6
Subject(s) - anaerobic exercise , cycle ergometer , rating of perceived exertion , ventilatory threshold , ventilation (architecture) , respiratory exchange ratio , core (optical fiber) , respiratory minute volume , vo2 max , incremental exercise , medicine , core temperature , zoology , physical therapy , lactate threshold , blood lactate , heart rate , respiratory system , blood pressure , physics , biology , optics , thermodynamics
During incremental exercise from rest to exhaustion, core temperature thresholds are evident at exercise intensities greater than that at the anaerobic threshold or the onset of blood lactate accumulation. The effect of aerobic fitness on these core temperature thresholds remains poorly understood. PURPOSE: To compare oesophageal temperature (T ES ) thresholds for exercise ventilation (V E ) between competitive, trained and untrained males during incremental exercise. HYPOTHESIS: Trained athletes will demonstrate a greater T ES threshold for V E than untrained males. Methods: Seven college‐aged competitive male cyclists with a VO 2MAX of 63.9 ± 3.7 mL•min ‐1 •kg ‐1 (mean ± SD) and 7 college‐aged untrained males with a VO 2MAX of 53.9 ± 3.5 mL•min ‐1 •kg ‐1 volunteered for the study that approved by the SFU Office of Research Ethics. V E and its components were measured with a breath‐by‐breath metabolic cart and volunteers pedaled an electrically braked cycle ergometer at an ambient temperature of ~22 o C. Each incremental exercise test started with a load of 60 W on the cycle ergometer that was incremented by 35 W/min until exhaustion. Core temperature thresholds from plots of ventilatory equivalents for oxygen (V E /VO 2 ) and carbon dioxide (V E /VCO 2 ) as a function of T ES were 1.3 ° C greater (P<0.01) in the trained vs. the untrained group. The trained group relative to the untrained cyclists had a higher (P<0.01) anaerobic threshold as determined from plots of V E /VO 2 and V E /VO 2 as a function of VO 2 . CONCLUSION: Evidence supports the hypothesis that increased aerobic fitness results in a higher core temperature threshold for V E during incremental exercise. Grant Funding Source : Supported by NSERC and CFI