A small open study of 27 volunteers showed that CoQ10 exerts antiarrhythmic effects in some individuals (Fujioka et al 1983).
SPORTS SUPPLEMENT/ERGOGENIC AID
Because CoQ10 is essential for energy metabolism, researchers have speculated that it may improve athletic performance. Eight clinical studies investigating the effects of CoQ10 supplementation on physical capacity were located, generally showing negative results (Bonetti et al 2000, Braun et al 1991, Laaksonen et al 1995, Malm et al 1997, Nielsen et al 1999, Porter et al 1995, Snider et al 1992, Weston et al 1997, Ylikoski et al 1997). Test doses of CoQ10 varied between 60 mg to 1 50 mg daily over time periods of 28 days to 8 weeks. Of these eight studies, only one double-blind crossover trial produced positive results on both objective and subjective parameters of physical performance (Ylikoski et al 1997). In that study 94% of athletes felt that CoQ10 had improved their performance and recovery times, compared with the 33% receiving placebo.
Of the others, one study found that 1 50 mg CoQ10 taken over 2 months had no effect on maximal oxygen consumption, lactate thresholds or forearm blood flow, although it did improve the subjective perceived level of vigour (Porter et al 1995). Another study demonstrated that CoQ10 did not alter physiological or metabolic Coenzyme Q10 305
parameters measured as part of cardiopulmonary exercise testing; however, it did
extend the time and the workload required to reach muscular exhaustion (Bonetti et al 2000). Five further clinical trials produced negative results.
One retrospective study found that muscle CoQ10 levels were positively related to exercise capacity and/or marathon performance, suggesting that runners with the highest levels performed better than those with lower levels (Karlsson et al 1996).
CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD)
At least two clinical trials have investigated the use of CoQ10 supplementation in COPD (Fujimoto et al 1993, Satta et al 1991). In one study, 20 patients with COPD were randomly assigned CoQ10 (50 mg) or placebo as part of their pulmonary rehabilitation program (Satta etal 1991). Treatment resulted in a 13% increase in maximum oxygen consumption and a 10% increase in maximum expired volume, both significant improvements. A dose of CoQ10 (90 mg) daily over 8 weeks was studied in a smaller trial of patients with COPD (Fujimoto et al 1993). Significantly elevated serum CoQ10 levels were associated with improved hypoxaemia at rest, but pulmonary function was unchanged.
Was this article helpful?
Metabolism. There isn’t perhaps a more frequently used word in the weight loss (and weight gain) vocabulary than this. Indeed, it’s not uncommon to overhear people talking about their struggles or triumphs over the holiday bulge or love handles in terms of whether their metabolism is working, or not.