title: [Clinical biochemical evaluation of central fatigue with 24-hour continuous exercise].
abstract: OBJECTIVE
  The present study was conducted to clarify the effects of ultra-marathon (ultra long-term aerobic exercise in which people run long distances) on the brain; examine the issue of central fatigue; verify the serotonin hypothesis of exercise-induced brain fatigue, and ascertain relationships between central fatigue and oxidative stress.
  
  
  METHODS
  Subjects consisted of 15 individuals (12 men, 3 women) who ran continuously for 24 h. Mean age was 44 +/- 9 years (range, 31 approximately 64 years). Blood tests were conducted: (1) before starting to run (around 09:00); (2) 16h after starting (02:00 the next day); and (3) just after the finish (around 10:00 the next day) to measure the serum levels of serotonin, melatonin, free tryptophan (f-Tp) and free fatty acid. At the same time, urine samples were collected to measure levels of urinary biopyrrins (BPn). Subjective symptoms were investigated using the Japanese version of the Profile of Mood States (POMS) instrument.
  
  
  RESULTS
  (1) Participants ran a mean (+/- SD) distance of 162.6 +/- 18.3 km. (2) There were not marked changes in serum serotonin levels. Serum melatonin levels at 3 time points were 3.4 +/- 0.6 pg/ml, 57.2 +/- 15.2pg/ml and 7.8 +/- 8.9pg/ml, respectively(p < 0.01 before start vs. 16h after start). Serum f-Trp levels at the 3 time points were 5.4 +/- 0.9 nmol/ml, 9.7 +/- 2.1 nmol/ml and 11.5 +/- 4.9 nmol/ml, respectively (p< 0.05 before start vs. just before finish). Free fatty acid levels were 0.42 +/- 0.10 nmol/ml, 1.26 +/- 0.11 nmol/ml and 1.39 +/- 0.23 nmol/ml, respectively (p < 0.01 before start vs. 16 hours after start) (p < 0.05 before start vs. just after finish). (3) Urinary BPn levels increased with time, from 1.2 +/- 0.7 nmol/ml to 2.6 +/- 1.0 nmol/ml to 4.0 +/- 1.5 nmol/ml, respectively (p < 0.01 before the start vs. 16 hours after the start). (4) In terms of POMS scores, fatigue score (Factor F) increased, but vitality score (Factor V) was high at all time points and did not demonstrate any marked changes. Scores for anger and hostility were low (Iceberg profile-type: convex type). Urinary BPn levels were correlated significantly with both serum f-Trp level and Factor F:(y = 8.41x + 2.5, r = 0.708, n = 42) and (y = 2.82x + 5.9, r = 0.568, n = 42), respectively. Urinary BPn thus reflected the degree of subjective fatigue with a high level of sensitivity.
  
  
  CONCLUSIONS
  The present results suggest that running continuously for 24h induces brain fatigue and that oxidative stress may be involved.
authors.affiliation: The Jikei University School of Medicine, Aoto Hospital Clinical Laboratory, Katsushika-ku, Tokyo 125-8506.
authors.forename: Makoto
authors.initials: M
authors.lastname: Ohta
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Hirai
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ono
authors.forename: Makoto
authors.initials: M
authors.lastname: Ohara
authors.forename: Shoji
authors.initials: S
authors.lastname: Saito
authors.forename: Shingo
authors.initials: S
authors.lastname: Horiguchi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Watanabe
authors.forename: Akiko
authors.initials: A
authors.lastname: Tokashiki
authors.forename: Akito
authors.initials: A
authors.lastname: Kawai
authors.forename: Takashi
authors.initials: T
authors.lastname: Andou
authors.forename: Izuru
authors.initials: I
authors.lastname: Shioji
authors.forename: Teruyuki
authors.initials: T
authors.lastname: Noguchi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Morizuka
authors.forename: Masato
authors.initials: M
authors.lastname: Suzuki
authors.forename: Akio
authors.initials: A
authors.lastname: Imanishi
authors.forename: Nobuakira
authors.initials: N
authors.lastname: Takeda
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Machida
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology*; D004177:Dipyrone / Q000652:urine; D015444:Exercise; D005221:Fatigue / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology; D012420:Running; D012701:Serotonin / Q000097:blood; D014364:Tryptophan / Q000097:blood
chemical_list: D012701:Serotonin; D004177:Dipyrone; D014364:Tryptophan