The purpose of this study was to investigate the effects of a 120 km desert running race (5 stages over 4 days) on the main physiologic parameters related to the individual aerobic work capacity. Incremental treadmill tests were carried out on 7 recreational long-distance runners (age: 50.4±11.8 years; body mass: 76.0±8.5 kg; mean±SD) before and 3–5 days after the competition. Maximal oxygen consumption (
 $$
\dot VO_{2max} 
$$
 ), ventilatory threshold and heart rate were obtained by standard methods; the mean energy cost of running (Cr) above resting was calculated during the same protocol from the slope of the oxygen consumption versus running speed. After the race, the subjects exhibited significant (p<0.05) reductions only in $$
\dot VO_{2max} 
$$
 (averaging 7%; from 46.7±5.1 to 43.2±4.4 ml · kg−1 · mm−1) and in maximal heart rate (averaging 3%; from 172.4±14.1 to 166.7±14.5 beats · min−1). Knowledge of Cr (3.78±0.31 J · kg−1 · m−1 and 3.74±0.48 J · kg−1 · m−1, before and after the race respectively) allowed us to estimate the overall daily energy requirement, about 20 850 kJ. $$
\dot VO_{2max} 
$$
 and the maximal heart rate seem to be the main variables affected by prolonged strenuous runs followed by insufficient rest periods.

Maximal oxygen consumption and energy cost of running after a long-lasting running race: the 100 km of Sahara

In 1973, the Institute of Environmental Stress of the University of California-Santa Barbara, under the direction of Steven M. Horvath, began a series of field and laboratory studies of marathon ru...

The University of California Institute of Environmental Stress marathon field studies

La réalisation d'un marathon n'affecte pas les performances aérobies mesurées en laboratoire chez des marathoniens de niveau national

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A Comparative Study of the Oxygen Uptake Between Nonmotorized and Motorized Treadmills

Environmental Stress marathon field studies The University of California Institute of

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.

Horvath Sm

Papers

Maximal aerobic power after competitive marathon running.