• Determinants of 800-m and 1500-m Running Performance Using Allometric Models

      Ingham, Stephen A.; Whyte, Gregory P.; Pedlar, Charles R.; Bailey, David M.; Dunman, Natalie; Nevill, Alan M. (American College of Sports Medicine, 2008)
      Purpose: To identify the optimal aerobic determinants of elite, middle-distance running (MDR) performance, using proportional allometric models. Methods: Sixty-two national and international male and female 800-m and 1500-m runners undertook an incremental exercise test to volitional exhaustion. Mean submaximal running economy (ECON), speed at lactate threshold (speedLT), maximum oxygen uptake (V˙ O2max), and speed associated with V˙ O2max (speedV˙ O2max) were paired with best performance times recorded within 30 d. The data were analyzed using a proportional power-function ANCOVA model. Results: The analysis identified significant differences in running speeds with main effects for sex and distance, with V˙ O2max and ECON as the covariate predictors (P G 0.0001). The results suggest a proportional curvilinear association between running speed and the ratio (V˙ O2maxIECONj0.71)0.35 explaining 95.9% of the variance in performance. The model was cross-validated with a further group of highly trained MDR, demonstrating strong agreement (95% limits, 0.05 T 0.29 mIsj1) between predicted and actual performance speeds (R 2 = 93.6%). The model indicates that for a male 1500-m runner with a V˙ O2max of 3.81 LIminj1 and ECON of 15 LIkmj1 to improve from 250 to 240 s, it would require a change in V˙ O2max from 3.81 to 4.28 LIminj1, an increase of $0.47 LIminj1. However, improving by the same margin of 10 s from 225 to 215 s would require a much greater increase in V˙ O2max, from 5.14 to 5.85 LIminj1 an increase of $0.71 LIminj1 (where ECON remains constant). Conclusion: A proportional curvilinear ratio of V˙ O2max divided by ECON explains 95.9% of the variance in MDR performance.
    • Enhancing the efficacy of the 20 m multistage shuttle run test

      Flouris, Andreas D.; Metsios, Giorgos S.; Koutedakis, Yiannis (BMJ Publishing Group Ltd, 2005)
      OBJECTIVE: Maximal oxygen uptake (Vo(2max)) of 44 ml kg(-1) min(-1) is an accepted criterion (Vo(2CR)) below which health and fitness for young male adults may be compromised. New algorithms validated for Vo(2CR) screening using the 20 m multistage shuttle run test (20mMST) were developed. METHODS: Vo(2max) was assessed in 110 males using a stationary gas analyser in a treadmill test (TT) and in 40 of these subjects using a portable gas analyser in the 20mMST. Vo(2max) predicted from the 20mMST in 70 subjects was used for cross validation. Two equations predicting Vo(2max) during 20mMST (EQ(MST)) and TT (EQ(TT)) were developed. RESULTS: Significant energy cost variance (EC(V)) was detected between TT and 20mMST (p<0.001), correlated significantly with subject height, and was a significant predictor of Vo(2max) differences between TT and 20mMST. The r(2) of EQ(MST) was 0.92 (p<0.001). Predicted Vo(2max) values from EQ(MST) correlated with directly measured 20mMST Vo(2max) at r = 0.96 (p<0.001). ANOVA detected no mean difference (p>0.05) between predicted and measured values. Prevalence of low fitness based on Vo(2CR) was 0.37. McNemar chi(2) indicated significant differences in sensitivity (p<0.001) and specificity (p<0.05) between the original 20mMST equation (EQ(LEG)) and EQ(TT), regarding Vo(2CR) screening. Cohen's kappa demonstrated higher agreement with TT Vo(2max) for EQ(TT) (p<0.001) than EQ(LEG) (p<0.05). TT Vo(2max) correlated with the end result of both EQ(LEG) and EQ(TT) at r = 0.75 (p<0.001). Unlike EQ(TT) (p>0.05), mean predicted Vo(2max) from EQ(LEG) was significantly higher compared to TT Vo(2max) (p<0.001). CONCLUSION: These algorithms increase the efficacy of 20mMST to accurately evaluate aspects of health and fitness.