Cardiorespiratory, kinematic, neuromuscular and metabolic characteristics during the recovery period after an ultramarathon race

Abstract

The aim of this study was to investigate the effects of exercise-induced muscle damage caused by a 90 km ultramarathon on submaximal oxygen consumption and stride length. The experimental group consisted of 11 male runners (39.7 ± 9.3 years) competing in a 90 km ultramarathon. Ten male runners (41.0 ± 10.8 years) who did not run the 90 km ultramarathon formed the control group. Maximum oxygen consumption and peak treadmill running speed were measured two weeks before the ultramarathon. Daily measurements of muscle pain and plasma creatine kinase (CK) activity were recorded for seven days after the ultramarathon. Muscle pain, plasma CK activity, and blood lactate concentrations were recorded before, and oxygen consumption, respiratory exchange ratio (RER), heart rate, rate of perceived exertion (RPE), and stride length were all measured during a 15-minute submaximal treadmill test seven days before the ultramarathon, and on days 4, 7, 14, 21, and 28 after the ultramarathon. Peak blood lactate concentrations were determined 3 minutes after the completion of each treadmill test. Plasma CK activity and muscle pain remained significantly elevated in the experimental group for two days (p < 0.00002) and four days (p < 0.02) respectively after the ultramarathon. There was a significant increase in the post-submaximal treadmill test blood lactate concentrations, compared to pre-test values for each day (p < 0.00001). Submaximal oxygen consumption was significantly reduced in the experimental group for up to 28 days (p < 0.0004), and stride length was significantly reduced for 14 days (p < 0.05) after the ultramarathon. Furthermore, in the experimental group RER was significantly increased for up to seven days (p < 0.05), and RPE was significantly increased for up to four days (p < 0.04) after the ultramarathon. In conclusion, the decreased submaximal oxygen consumption following the ultramarathon may be interpreted as a positive training adaptation. However, other responses to the ultramarathon were not compatible with improved running performance. Furthermore, symptoms other than pain should be used to define the recovery period after an ultramarathon race.