MEKJAVIC, I. B., J. A. EXNER, P. A. TESCH, and O. EIKEN. Hyperbaric oxygen therapy does not affect recovery from delayed onset muscle soreness. Med. Sci. Sports Exerc., Vol. 32, No. 3, pp. 558–563, 2000.
Purpose: 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 (PIO2 = 0.2 ATA; placebo group) or a hyperoxic gas mixture (PIO2 = 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.
Acute bouts of high-force eccentric muscle actions can cause delayed onset muscle soreness (DOMS) (1,2,6,7,12,15,16,22,25), which apart from muscle pain, is signified by morphological changes and elevations of muscle proteins, reflecting muscle damage, muscle stiffness, decrements in force production, and edema formation (2–4,6,7,13,14,19).
The precise mechanisms underlying the development of DOMS remain unresolved, though a multitude of factors have been suggested as possible causes in the development of DOMS (2,4,7,12). Concomitant with the several proposed theories regarding the development of DOMS (5,8,27) are numerous suggestions for the treatment of DOMS, including anti-inflammatory drugs, massage, and light exercise (10,11,23,28,29,33).
The use of hyperbaric oxygen therapy (HBOT) to treat exercise-related injuries has recently become popular among elite athletes and professional sports teams (20, 30). HBOT is a clinical treatment in which patients breathe 100% oxygen at elevated ambient pressures, ensuring that the tissue partial pressure of oxygen is substantially elevated (18). The ability of HBOT to provide hyperoxygenated blood to damaged ischemic tissue has been shown to accelerate healing (9).
In view of anecdotal reports of accelerated recovery rates from various sports injuries including DOMS (20), we performed a controlled blinded study to investigate the potential benefits of HBOT on the rate of recovery of muscle strength, the duration of the perceived muscle soreness, and edema.
Department of Sports & Exercise Science, Faculty of Science, University of Portsmouth, Portsmouth, UNITED KINGDOM; Faculty of Medicine, University of Ljubljana, Ljubljana, SLOVENIA; and Division of Clinical Physiology, Karolinska Institute, Huddinge Hospital, S-14186 Huddinge, SWEDEN; Swedish Defence Research Establishment, Aviation Medicine, Karolinska Institute, S-17177 Stockholm, Sweden
Submitted for publication July 1998.
Accepted for publication March 1999.
Address for correspondence: Igor B. Mekjavic, Department of Automation, Biocybernetics and Robotics, Institute Jozef Stefan, Jamova 39, 1000 Ljubljana, Slovenia. E-mail: firstname.lastname@example.org.