title: Muscle and plasma coenzyme Q10 concentration, aerobic power and exercise economy of healthy men in response to four weeks of supplementation.
abstract: OBJECTIVE
  To investigate whether 4 weeks of oral supplementation with coenzyme Q10 (CoQ10) would increase its concentration in skeletal muscle, and affect aerobic power (VO2max) and oxygen consumption during submaximal exercise in healthy, physically active men.
  
  
  METHODS
  Six volunteers with an average (+/-SD) age of 29.7+/-7.2 years and VO2max of 39.4+/-8.5 mL.kg-1.min-1, participated in a single-blind trial. The experiment consisted of 4 2-week phases, in the order of placebo run-in, CoQ10 supplementation (150 mg daily), CoQ10 (150 mg) plus vitamin E (1,000 IU daily), and placebo wash-out. A three-stage cycle economy test (4 minutes at each of 50, 100, and 150 watts), followed by a VO2max test (25 watts increment every minute till exhaustion), were performed prior to the supplementation and at the end of each phase. Blood samples were taken pre and post each VO2max test, and biopsy samples were obtained from the vastus lateralis muscle pre and post the 4 weeks of CoQ10 supplementation.
  
  
  RESULTS
  The plasma CoQ10 concentration was significantly elevated by the supplementation (P<0.05), however, it did not vary significantly pre and post each exercise test (P>0.05). The muscle CoQ10 concentration, VO2max ventilatory threshold, exercise economy and oxygen deficit showed no significant changes in response to the supplementation.
  
  
  CONCLUSIONS
  It was speculated that the non-significant effects of supplementation in healthy, non CoQ10-deficient men could be due to either that the mitochondrial membrane is normally saturated with CoQ10, or that the selected exercise testing protocol and variables were not sensitive enough to detect the effects.
authors.affiliation: School of Exercise Science and Sport Management, Southern Cross University, Lismore, Australia. szhou@scu.edu.au
authors.forename: S
authors.initials: S
authors.lastname: Zhou
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: A
authors.initials: A
authors.lastname: Davie
authors.forename: S
authors.initials: S
authors.lastname: Marshall-Gradisnik
authors.forename: H
authors.initials: H
authors.lastname: Hu
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.forename: D
authors.initials: D
authors.lastname: Brushett
mesh_terms: D000328:Adult; D003067:Coenzymes; D019587:Dietary Supplements; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D008297:Male; D009132:Muscles / Q000187:drug effects / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D011446:Prospective Studies; D052097:Quadriceps Muscle / Q000098:blood supply / Q000502:physiology; D013997:Time Factors; D014451:Ubiquinone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D014810:Vitamin E
chemical_list: D003067:Coenzymes; D014451:Ubiquinone; D014810:Vitamin E; C024989:coenzyme Q10