Table 3: Relative contents of the high energy phosphates and the fibre type distribution for the 4 measurement points. 31P-MRS measurements and biopsies were performed initially ( ) and after a period of speed-strength ( ), endurance ( ), and de-training ( ). Fibre types were classified into slow-twitch more oxidative type I and fast-twitch more glycolytic type II with subtypes IIa and IIb (ATPase reaction).

Median ± SEMinMaxMedian ± SEMinMaxMedian ± SEMinMaxMedian ± SEMinMax

MRS
  [PCr]/[ ] 4.919.16 5.769.56 6.1010.09 6.2711.38
  [PCr]/[βATP] 2.954.70 3.084.97 3.454.82 3.415.14
  [PCr + ]/[βATP] 4.265.35 3.615.52 3.825.55 3.945.73

Biopsy
 Type I (%) 33.085.3 43.583.8 55.883.5 21.883.8
 Type II (%) 14.738.1 16.256.5 16.544.2 16.278.2
 Type IIa (%) 12.437.4 15.748.4 11.934.0 15.765.5
 Type IIb (%) 0.05.1 0.511.7 0.510.2 0.512.7

SE: standard error. MIN: minimum. MAX: maximum. : preinterventional. : after speed-strength training; : after endurance training. : after de-training.