Until recently, assessment of muscle metabolism was only possible via biopsy sampling, which is an invasive procedure. 31P-Nuclear magnetic resonance spectroscopy (31P-NMRS) nowadays offers a feasible way to study aerobic and anaerobic muscle metabolism non-invasively. Therefore, the aim of the present study was to assess muscle fibre properties of sprint-trained and endurance- trained athletes by 31P MRS and appropriate motor performance tests. Methods: Ten competitive athletes, stratified according to their discipline and activity into five sprint-trained (SG) and five endurancetrained (EG) athletes, participated in the present study. Each athlete completed a 31P MRS assessing high energy phosphates, intracellular pH and muscle volume, a Wingate test (WAnT) measuring peak power (PP), mean power (MP), fatigue index (FI) and a countermovementjump measuring jump height. Additionally, lactate was taken 3 minutes after the end of the WAnT. Results: Lateralis PCr content of the EG was significantly higher than in the SG during the second recovery phase of MRS. PCr concentration of the lateralis muscle in the second recovery phase and MP.kg-1 correlated negatively: r = -0.728 (p </=; 0.05). Muscle volume of the m. quadriceps was significantly greater in SG than in EG (2406 ± 250 cm3 and 2866 ± 339 cm3, p </=; 0.05). The SG exhibited significantly higher values for PP, MP, FI and lactate as well as for jump height (p </=; 0.01). Lactate post WAnT correlated significantly (p </=; 0.01) with jump height (r = 0.97). T-Tests for independent variables and a logistic regression analysis were carried out. > Conclusion: Skeletal muscle reveals considerable differences between endurance and sprint athletes. 31P MRS in combination with motor performance tests therefore seems to be a suitable tool to display differences in skeletal muscle properties of subjects with a supposed difference in their muscle fibre distribution.
© Copyright 2009 14th annual Congress of the European College of Sport Science, Oslo/Norway, June 24-27, 2009, Book of Abstracts. Veröffentlicht von The Norwegian School of Sport Sciences. Alle Rechte vorbehalten.