Branched-chain amino acids (valine, leucine, and isoleucine; BCAAs) are abundant selleck screening library and catabolized in the skeletal muscle, and they help to inhibit protein breakdown [4] and enhance protein synthesis [5]. BCAAs have been reported in many studies to attenuate DOMS and muscle damage induced by exercise [4, 6–11]. Shimomura et al. reported that BCAA supplementation prior to squat exercises decreased DOMS AZD5363 ic50 within a few days after exercise [7, 8]. Furthermore, the beneficial effects of BCAA supplementation on DOMS together with the inhibition of muscle damage was also observed for a training program involving trained long-distance runners [4] and in cycling exercise [9, 10]. In contrast, a study

by Jackman et al. found no attenuating effects of BCAA supplementation on DOMS in the quadriceps muscle with the knee extended or on inflammation during the recovery period following high-intensity knee extension exercise, but DOMS was attenuated when measured with the knee flexed [11]. Thus, the positive effects of BCAA supplementation on DOMS and muscle damage were weak in high-intensity exercise. Previous studies have evaluated the combined effects of various nutrients and BCAA supplements on DOMS and muscle damage. Stock et al. examined the combined effect of leucine GSK458 molecular weight supplementation and a carbohydrate beverage on DOMS and serum muscle damage markers

during the recovery period following squat exercises; however, no significant Protirelin effects

were found before or after exercise [12]. Furthermore, the combination of protein (free-form amino acids including BCAA) and carbohydrate supplements given before and after ECC had no effect on muscle damage, loss of strength, or muscle soreness [13]. Therefore, combining BCAAs with other anti-inflammatory nutrients might be beneficial for alleviating DOMS and muscle damage. Taurine (2-aminoethanesulfonic acid), which is abundant in skeletal muscle, has been reported to have many physiological and pharmacological actions, including membrane stabilization, anti-oxidation, osmoregulation, modulation of ion flux, and control of Ca2+ homeostasis, in addition to playing roles as a neurotransmitter and neuromodulator [14]. In particular, it was reported that taurine has a cytoprotective effect against free radical-mediated skeletal muscle injury induced by downhill running in rats [15, 16]. The authors also confirmed that oral taurine administration in rats reduces exercise- and drug-induced oxidative stress [17, 18]. Interestingly, a multi-nutrient supplement containing BCAA and taurine as well as some vitamin B and plant extracts improved inflammation and joint pain in middle-age individuals [19]. Therefore, we hypothesized that taurine might enhance the beneficial effect of BCAA on DOMS and muscle damage induced by exercise.