Int J Sports Med 2011; 32(6): 422-428
DOI: 10.1055/s-0031-1271676
Training & Testing

© Georg Thieme Verlag KG Stuttgart · New York

Anaerobic Capacity: Effect of Computational Method

D. A. Noordhof1 , A. M. T. Vink1 , J. J. de Koning1, , 2 , C. Foster1, , 2
  • 1VU University, Faculty of Human Movement Sciences, Amsterdam, The Netherlands
  • 2University of Wisconsin La Crosse, Department of Exercise and Sports Science, La Crosse, Wisconsin, USA
Further Information

Publication History

accepted after revision December 30, 2010

Publication Date:
11 May 2011 (online)

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Abstract

Anaerobic capacity (AnC) can be estimated by subtracting VO2 consumed from VO2 demand, which can be estimated from multiple submaximal exercise bouts or by gross efficiency (GE), requiring one submaximal bout. This study compares AnC using the MAOD and GE method. The precision of estimated VO2 demand and AnC, determined by MAOD using 3 power output – VO2 regressions, based on VO2 from min 8–10 (10 − Y), during min 4 without (4 − Y) and with forced y-intercept (4+Y), and from GE was evaluated by the 95% confidence interval (CI). Well-trained males (n=15) performed submaximal exercise tests to establish VO2 demand with the MAOD and GE method. To determine AnC subjects completed a constant power output trial. The 3 MAOD procedures and GE method had no significant difference for VO2 demand and AnC. The 4+Y MAOD procedure and GE method resulted in a smaller 95% CI of VO2 demand and AnC than the 10 − Y (p<0.05; p<0.01) and 4 – Y (p<0.001; p<0.01) MAOD procedures. Therefore, the 4+Y MAOD procedure and GE method are preferred for estimating AnC, but as individual differences exist, they cannot be used interchangeably.

References

Appendix

Calculating the 95% CI of a regression line

The observed data is represented as x i and y i (i=1, 2, …, n), which results in the below presented equations for the regression line without and with fixed value for the y-intercept.

Regression – without fixed y-intercept

Sxx (xi – mean(x))2

sum of squares of x

Sxy=Σ((xi – mean(x)) · (yi – mean(y)))

sum op products

b=Sxy/Sxx

slope

a=mean(y) – b·mean(x)

y-intercept

ŷi=a+b·xi

regression equation

εi=yi – ŷi

residuals

s ε= ((Σε i 2)/(n−2))

standard deviation of the residuals

seŷ=s ε·(1/n+(xi mean(x)) 2/Sxx)

standard error of the estimate ŷ

95% CI=ŷi ±t(n–1) ·seŷ

95% confidence interval based on a t-distribution

Regression – with fixed y-intercept

y=yfixedyintercept

Sxx xi 2

sum of squares of x

S xy=Σ(xi  · yi)

sum op products

b=Sxy/Sxx

slope

ŷi =b·xi

regression equation

εi =yi ŷi

residuals

s ε =((Σε i 2)/(n−1))

standard deviation of the residuals

seŷ=s ε· √(xi 2/Sxx)

standard error of the estimate ŷ

95% CI=ŷi ±t(n−1) ·seŷ

95% confidence interval based on a t-distribution

Correspondence

Dionne Adriana NoordhofMSc 

VU University

Faculty of Human Movement

Sciences

van der Boechorststraat 9

1081 BT Amsterdam

The Netherlands

Phone: + 31/20/59 82000

Fax: + 31/20/59 88529

Email: d.a.noordhof@vu.nl