Coenzyme Q10 supplementation downregulates the increase of monocytes expressing toll-like receptor 4 in response to 6-day intensive training in kendo athletes.

This study examined changes in toll-like receptor 4 (TLR-4)-expressing monocytes and lymphocyte subpopulations in response to continuous intensive exercise training in athletes, as well as the effect of coenzyme Q10 (CoQ10) supplementation on these changes. Eighteen male elite kendo athletes in Japan were randomly assigned to a CoQ10-supplementation group (n = 9) or a placebo-supplementation group (n = 9) using a double-blind method. Subjects in the CoQ10 group took 300 mg CoQ10 per day for 20 days. Subjects in the placebo group took the same dosage of placebo. All subjects practiced kendo 5.5 h per day for 6 consecutive days during the study period. Blood samples were collected 2 weeks before training, on the first day (day 1), third day (day 3), and fifth day of training (day 5), and 1 week after the training period (post-training) to ascertain TLR-4+/CD14+ monocyte and lymphocyte subpopulations (CD3+, CD4+, CD8+, CD28+/CD4+, CD28+/CD8+, and CD56+/CD3− cells) using flow cytometry analysis. The group × t...