ISSN:
1600-0838
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
,
Sports Science
Notes:
The differences in ergometric power and in biochemical characteristics of the vastus lateralis muscle (VL) between 100-m and 800-m runners (R) were studied in 2 groups of 8 male athletes (100m-R and 800m-R) during a 45-s all-out cycle ergometer exercise. Peak power (PP), mean power (MP) and percentage of fatigue were respectively 24%, 13% and 24% higher in the 100m-R than in 800m-R, whereas total work output was similar in both groups. In 100m-R, there was a higher percentage of fast twitch (FT) fibres, a higher buffer (mß) titration capacity and a lower oxidative potential expressed by citrate synthase, 3-hydroxyacyi-CoA dehydrogenase and cytochrome oxidase than in 800m-R. During all-out exercise, muscle lactate [lact] and protons [H+] accumulated significantly more in 100m-R than in 800m-R with a corresponding muscle pH of 6.49 ± 0.07 and 6.63 ± 0.12. However, the decreases in adenosine triphosphate (ATP) and creatine phosphate were not different between the two groups. Significant correlations were found between PP (or % fatigue) and Δ[H+], Δ[lact], Δ[ATP], %FT or oxidative capacity when the two groups were pooled together. It was concluded mat the difference in %FT, in titration mß and in the contribution of the glycolytic and oxidative processes observed in VL between 100m-R (pure anaerobic training) and 800m-R (mixed aerobic-anaerobic training) are determinant factors in the pattern of energy output during supramaximal exercise.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1600-0838.1992.tb00321.x
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