title: Ultradian rhythms in extended performance.
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D001288:Attention; D001683:Biological Clocks; D002940:Circadian Rhythm; D004562:Electrocardiography; D006339:Heart Rate; D006801:Humans; D008297:Male; D005082:Physical Exertion; D011930:Reaction Time; D013312:Stress, Physiological; D013647:Task Performance and Analysis; D013997:Time Factors