BackgroundThe metabolomics approach, aiming to link variation of metabolic profile to pathologic conditions, is a vital tool for personalized medicine and biomarker discovery. In the context of athletes’ monitoring and injury prevention, measuring the dynamic metabolic changes resulting from pathologic conditions is crucial.ObjectiveWe aimed to develop an NMR-based metabolomic workflow to spot specific metabolic signature of athletes’ fitness and recovery. Our purpose was to provide valuable information about the metabolic status of athletes by comparing metabolomic data coming from two group of individuals: Ultra-trail athletes (UT) and, sedentary individuals.DesignLongitudinal, cohort studySettingUT individuals were participating to the UltraTour, a 67 km ultra-trail running, 1500 D+ in Liège (Belgium). Sedentary individuals ran 1 hour on a treadmill at the maximum of their capacity.Participants20 UT participants, 15 sedentary.Intervention (or Assessment of risk factors)Blood samples were collected at three time points: before (TO), immediately after (T1), and three hours after the start of their effort (T3). NMR-based metabolomic analysis was employed to analyze intragroup and intergroup metabolic variations.Main outcome measurements1H-NMR spectra were recorded and processed through an in-house pipeline to generate metabolic profiles. Intragroup and intergroup variations were analyzed using non-discriminant PCA models dedicated to multivariate analysis.ResultsIntragroup metabolic profile changes from T0 to T3 were observed for both groups. Indeed, three hours of recovery were insufficient for athletes to return to their baseline metabolic status. Significant differences between athletes and sedentary individuals were also highlighted. ConclusionThis proof-of-concept study spotted the importance of metabolomics approach in the field of athletes’ follow-up, performance monitoring and injury prevention. Indeed, by following the metabolic changes over the time, we can assess the fitness of the studied individuals and gather information about their recovery and avoid situation of high-risk of muscle injury.