Maximal aerobic power after competitive marathon running.

We evaluated the ability of a group of male runners (n = 4) to do maximal and submaximal exercise before and after they ran a competitive marathon (42.2 km) race. VO2max was determined 3 to 6 times in each runner, on alternate days, 1-4 weeks prior to the race, and again an equal number of times, once the runners had recovered from muscle soreness (avg. 7 days) after the race. Each test consisted of a 10 min treadmill walk (8.6% slope, 94 m.min-1 [3.5 miles.h-1]) followed by a 5 min run (8.6% slope, 188 m.min-1 [7 miles.h-1]). After this time, the speed was increased 10 m.min-1 every minute until exhaustion. No differences in VO2 were observed during submaximal exercise, and no reduction in VO2max occurred. One runner, however, exhibited a substantial and consistent increase in VO2max after the marathon (73.6 +/- 1.5 (SE) to 79.9 +/- 0.7 mL.kg-1.min-1, p less than 0.05). Treadmill exercise-induced increases in hematocrit, blood hemoglobin, and plasma protein, cortisol, lactate and norepinephrine concentrations were unaltered after the marathon. We conclude that, following a period of sufficient recovery from muscle soreness, oxygen delivery and utilization mechanisms remain intact after marathon running.