UBC Theses and Dissertations
The effect of continuous and interval warm-up on post-exercise bronchoconstriction McLuckie, Sandra Lynn
Several elite and recreational athletes experience an increase in airway resistance following physical exertion. Warm-up prior to exercise has been suggested as a non-invasive means of reducing or eliminating this condition. To determine the effect of warm-up on post-exercise bronchoconstriction, twelve moderately trained exercise-induced asthmatics (age = 26.5 yrs; ht. = 169.2 cm; wt. = 64.3 kg; VO₂ max = 52.5ml.kg⁻¹ .min⁻¹; PC20 = 1.00 mg.ml⁻¹) were tested under three experimental conditions. Continuous warm-up (CW) consisted of 15 minutes of treadmill running at a velocity corresponding to 60% VO₂ max followed by an exercise-challenge test (ET= 6 minutes at 90% VO₂ max). The interval warm-up (IW) involved 8 x 30 second sprints at an intensity equivalent to 100% V0₂ max (1.5 minutes rest between sprints), followed by an ET. The no warm-up (NW) involved only the ET, and acted as the control. FEV₁⋅₀ , FVC, and MMEFR were measured via the Breon spirometer prior to warm-up (CW and IW), ET, and every 2 minutes during a 25 minute passive recovery period. Post-exercise bronchoconstriction was taken as the largest decrease in %FEV₁⋅₀, %FVC, and %MMEFR during the recovery period. Significant differences were detected in %FEV₁⋅₀ (34.6, 50.0, 30.0: p = 0.009); %FVC (16.7, 30.2, 10.7: p = 0.05); and %MMEFR ((29.7, 43.4, 21.0: p = 0.03), in comparing NW, CW, and IW, respectively. A Scheffe's test detected significance (p<0.05) between NW and CW for all 3 dependent variables. No significance between NW and IW or IW and CW occurred. This data indicates that a continuous warm-up of 15 minutes at 60% V0₂ max can significantly decrease post-exercise bronchoconstriction in moderately trained athletes.
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