 3.1.- SUBJECTS This is a randomized, controled, double blind trial. The experimental subjects that will take part in this study are Spanish Fire Department. We will try to get a total sample of 100 subjects on each study to constitute two groups of 50 subjects, one experimental group will receive ubiquinol capsules 200 mgday during 2 weeks and a control group receiving placebo during the same period of time. Likewise, a nutritional survey will be realized, with follow-up of 72h, to assure that the all the subjects consume similar diets and these will not interfere with the study. They will be informed about the characteristics of the study and we will get informed consent form them. 