Changes in perceived mental fatigue, physical fatigue and mood state during a 4-day national junior orienteering competition preparation camp

Mental fatigue (MF) has been shown to acutely impair the psychological responses and endurance running performance of orienteers. This study aimed to explore MF levels experienced by orienteers during a 4-day competition preparation camp that consisted of simulated sprint, middle-distance, long-distance, relay and night races. Eleven national junior orienteers participated in the study (age: 15-17 years, height: 1.69 +/- 0.07 m and body mass: 59.9 +/- 5.22 kg). Subjective ratings of MF, motivation, stress, physical fatigue (PF) and tiredness were measured using a 100-mm visual analogue scale. The Brunel Mood Scale (BRUMS) was utilized to assess the mood state of the orienteers. The self-report measures were taken within 30 min of waking, immediately after the post-training session, and after 24 and 48 h following the final training session. The pre-post orienteering training combined analysis showed that there was a moderate increase in perceived MF (ES = 1.06 [0.66, 1.45]), PF (ES = 1.07 [0.69, 1.45]) and BRUMS fatigue (ES = 0.74 [0.4, 1.1]) after orienteering training. At 48 h post the final training session, MF remained moderately elevated (ES = 0.86 [-0.07, 1.75]), while PF also remained elevated to a small extent (ES = 0.46 [-0.46, 1.39]) compared to the pre-training values. A moderate impairment was still observed in BRUMS vigor (ES = -1.02 [-1.65, -0.36]), but BRUMS confusion scores were moderately lower (ES = -0.85 [-1.71, 0.04]) than pre-training values. This study found that orienteering training induced acute MF, persisting for at least 48 h after the final session.