title: Hyperbaric oxygen therapy does not affect recovery from delayed onset muscle soreness.
abstract: OBJECTIVE
  This study investigated whether hyperbaric oxygen therapy (HBOT) improves recovery after exercise-induced muscle injury.
  
  
  METHODS
  Healthy male subjects (N = 24) were randomly assigned to either a placebo group or a HBOT group. Subjects were tested for maximal isometric strength (preexercise) of their right elbow flexors. Each subject then completed a high-force eccentric workout of the elbow flexor muscle group to induce delayed onset muscle soreness (DOMS). On the seven successive days after this workout, the subjects were exposed to a hyperbaric environment of 2.5 ATA for 60 min, inspiring either a normoxic mixture (P(I)O2 = 0.2 ATA; placebo group) or a hyperoxic gas mixture (P(I)O2 = 2.5 ATA; HBOT group). Before the eccentric workout and daily for the next 10 d, measurements were obtained regarding: maximal isometric muscle strength of the elbow flexor muscles, right upper arm circumferences, and rating of the perceived muscle soreness.
  
  
  RESULTS
  Isometric strength decreased significantly from preexercise levels of 25.1 +/- 3.8 kp to postexercise levels of 12.0 +/- 4.6 kp, for the HBOT group, and from 24.6 +/- 3.4 kp to 12.5 +/- 3.7 kp, respectively, for the placebo group. Over the 10-d recovery period, there was no difference in the rate of recovery of muscle strength between the two groups. Perceived soreness peaked at about 48 h after exercise with no difference between groups. Also, the exercise-induced increases in arm circumference were similar in the two groups.
  
  
  CONCLUSIONS
  These results indicate that HBOT is not an effective therapy for the treatment of DOMS.
authors.affiliation: Department of Sports & Exercise Science, Faculty of Science, University of Portsmouth, United Kingdom. eubs@guest.arnes.si
authors.forename: I B
authors.initials: IB
authors.lastname: Mekjavic
authors.forename: J A
authors.initials: JA
authors.lastname: Exner
authors.forename: P A
authors.initials: PA
authors.lastname: Tesch
authors.forename: O
authors.initials: O
authors.lastname: Eiken
mesh_terms: D000328:Adult; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D006801:Humans; D006931:Hyperbaric Oxygenation; D008297:Male; D018763:Muscle Fatigue; D018482:Muscle, Skeletal / Q000293:injuries*; D010146:Pain; D016896:Treatment Outcome