Portal de Periódicos da CAPES

Power and metabolic responses during supramaximal exercise in 100‐m and 800‐m runners

1992; Wiley; Volume: 2; Issue: 2 Linguagem: Inglês

10.1111/j.1600-0838.1992.tb00321.x

1600-0838

Christian Denis, M. T. Linossler, D. Dormols, Sabino Padilla, A. Geyssant, J. R. Lacour, Omri Inbar,

Exercise and Physiological Responses

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.