Objectives: The aim of this study was to: (a) examine the time courses of runners’ recovery-stress states within the month following a demanding Mountain Ultra-Marathon (MUM) race; and (b) explore the role of primary and secondary appraisals in these trajectories. Design: A seven-wave one-month longitudinal design was used with one measurement point within two days before the race to measure appraisals and six time points within the month following the race to assess recovery-stress states experienced by athletes. Method: A multilevel growth curve analysis approach was used among a sample of 29 MUM runners. Results: Recovery-stress states were characterized by distinct trajectories during the month following MUM race. Results of multilevel growth curve analyses showed significant linear increases of general and total recovery, significant linear decreases of general, sport-specific and total stress and a positive quadratic effect of squared time (U shape over time) on specific recovery. Primary appraisal significantly positively predicted levels of sport-specific recovery, total, general and sport-specific stress and significantly negatively predicted total and general recovery. Secondary appraisal significantly negatively predicted total and general stress. Conclusions: This study provided insights into the role played by appraisals on the recovery-stress states experienced by MUM runners the month following a demanding MUM race. Operational strategies were suggested in order to optimize the recovery-stress balance and in turn psychological adaptation processes in response to an ultra-endurance race.