Abstract

Running economy is a determinant of performance in distance running competitions and the effect of fatigue on running economy is important to all distance runners. Studies on the association between running economy and fatigue yielded equivocal findings, and therefore, the purpose of the present investigation was to examine short-term changes in sub-maximal running economy following a ultra¬distance run. Ten female distance runners participating mainly in events longer than 32 kilometers, and training for the Comrades Marathon, volunteered to participate in the study. Laboratory procedures took place six weeks before the race and involved measurements of height, weight, percentage body fat and the direct determination of maximal oxygen uptake (VO2max). On a separate visit to the laboratory (two days after the VO2max test), an economy run was performed for six minutes at a fixed speed of 15 km/hr, after a warm-up of approximately 10 minutes at a speed comfortable for each subject. The 1999 Comrades Marathon served as the fatiguing run. The subjects underwent the post-Comrades marathon economy run three weeks after the race. Results indicated statistically significant differences (p < 0.05) between the pre-Comrades and the post-Comrades marathon values in terms of stabilised VO2/kg (43.1 ± 3.06 ml/kg/min vs. 46.4 ± 212 ml/kg/min) and the % VO2 max utilized at 15km/h (87.93 ± 7.63 vs. 94.91 ± 4.06 %. In conclusion, the ultra-distance 1999 Comrades Marathon substantially affected aerobic efficiency in female athletes. Verf.-Referat