TM Lehr
L Young


T.M. Lehr,L. Young

The University of Montana Western, Dillon, MT

Competitive runners train to increase their aerobic fitness and economy. PURPOSE: The purpose of this study is to compare aerobic fitness parameters in competitive runners from southwest Montana over the time span of one calendar year. METHODS: Fourteen competitive runners volunteered for this study (N=14, 8M, 18.75 ± 0.5 yr., 20.66 ± 0.99 kg/m2BMI and 6F, 19.75 ± 0.5 yr., 20.45 ± 1.86 kg/m2BMI). Subjects completed a graded exercise test on a treadmill connected to an open-circuit computerized gas analysis system at 4 assessment periods throughout a year (W17, S18, F18, W18) for the determination of VO2peak, total time to exhaustion (TTE), maximal respiratory exchange ratio (max RER), and Time at RER>1.0. The graded exercise test consisted of a 3-minute warm-up at 3.5 miles per hour (mph). Males completed a ramp protocol initiated at 7 mph and increased in speed 1 mph every 90 seconds until 12 mph. At 12 mph, a 0.5% grade increase occurred every 90 seconds until volitional exhaustion. Female subjects completed a protocol initiated at 6 mph and increasing 1 mph every 90 seconds until 10mph; followed by 0.5% grade increase every 90 seconds until volitional exhaustion. Verbal encouragement was provided in all tests. A Kruskal-Wallis ANOVA with post-hoc tests were calculated (alpha p = <0.05) to compare BMI, VO2peak, TTE, max RER, and Time at RER>1.0between each assessment period for all subjects. A repeated measures ANOVA with planned comparisons was used to evaluate outcomes within genders. RESULTS: There were no differences in BMI, VO2peak, TTE or Time at RER>1.0 within males or females at any assessment time point. Combined male and female data (N=14), revealed an increase in VO2peak in W17 vs. W18 (52.61 ± 7.66; 65.5 ± 9.85 ml/kg/min-1, p=0.04). Max RER decreased in W17 vs. F18 (1.13 ± 0.03; 1.05 ± 0.01, p>0.00) and S17 vs. W18 (1.11 ± 0.04; 1.05 ± 0.01, p=0.03), in addition Time at RER>1.0 was decreased in W17 vs. W18 (2:46 ± 1:03; 1:33 ± 0:12 min, p=0.02). CONCLUSION: An increase in VO2peak was only observed in the initial (W17) assessment period, while max RER and Time at RER>1.0 continued to decline throughout the year. This occurred without a concurrent change in VO2peak. A decrease in Time at RER>1.0 could suggest an increase in fat utilization with training, although further testing is needed to evaluate these conclusions.

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