Neuromuscular characteristics and fatigue in endurance and sprint athletes during a new anaerobic power test

The purpose of this study was to investigate neuromuscular and energy performance characteristics of anaerobic power and capacity and the development of fatigue. Ten endurance and ten sprint athletes performed a new maximal anaerobic running power test (MARP), which consisted ofn x 20-s runs on a treadmill with 100-s recovery between the runs. Blood lactate concentration [la^–]_b was measured after each run to determine submaximal and maximal indices of anaerobic power (P_3mmol·1^–1,P_5mmol·1^–1,P_10mmol·1^–1andP_max) which was expressed as the oxygen demand of the runs according to the American College of Sports Medicine equation: the oxygen uptake (ml·kg^–1·min^–1)=0.2·velocity (m·min^–1) +0.9·slope of treadmill (frac)·velocity (m·min^–1)+3.5. The height of rise of the centre of gravity of the counter movement jumps before (CMJ_rest) and during (CMJ) the MARP test, as well as the time of force production (t_F) and electromyographic (EMG) activity of the leg muscles of CMJ performed after each run were used to describe the neuromuscular performance characteristics. The maximal oxygen uptake (_max), anaerobic and aerobic thresholds were determined in the_max test, which consisted ofn x 3-min runs on the treadmill. In the MARP-testP_max did not differ significantly between the endurance [116 (SD 6) ml·kg^–1·min^–1] and sprint [120 (SD 4) ml·kg^–1·min^–1] groups, even though CMJ_rest and peak [la^–]_b were significantly higher and_max was significantly lower in the sprint group than in the endurance group and CMJ_rest height correlated withP_max (r=0.50,P<0.05). The endurance athletes had significantly higher mean values ofP_3mmol·1^–1andP_5mmol·1^–1[89 (SD 7) vs 76 (SD 8) ml·kg^–1·min^–,P<0.001 and 101 (SD 5) vs 90 (SD 8) ml·kg^–1·min^–1,P<0.01. Significant positive correlations were observed between theP_3mmol·l^–1and_max, anaerobic and aerobic thresholds. In the sprint group CMJ and the averaged integrated iEMG decreased andt_F increased significantly during the MARP test, while no significant changes occurred in the endurance group. The present findings would suggest thatP_max reflected in the main the lactacid power and capacity and to a smaller extent alactacid power and capacity. The duration of the MARP test and the large number of CMJ may have induced considerable energy and neuromuscular fatigue in the sprint athletes preventing them from producing their highest alactacidP_max at the end of the MARP test. Due to lower submaximal [la^–]_b (anaerobic sprinting economy) the endurance athletes were able to reach almost the sameP_max as the sprint athletes.