Recently, alternative forms of creatine, such as creatine ethyl ester (CEE) and Kre Alkalyn (KA) have been marketed as superior forms of creatine to CM; Selleck XAV 939 however, as of this time these claims have not been supported by scientific studies. Tallon and Child [137, 138] found that a greater portion of CEE and KA are degraded in the stomach than CM. Additionally, recent PD-1/PD-L1 tumor investigations have shown that 28–42 days of CEE or KA supplementation did not increase muscle creatine concentrations more than CM [139, 140]. Thus, it appears
that CM may be the most effective form of creatine. Beta-alanine Beta-alanine (BA) is becoming an increasingly popular supplement among bodybuilders. Once consumed, BA enters the circulation and is up-taken by skeletal muscle where it is used to synthesize carnosine, a pH buffer in muscle that is particularly important LY2835219 supplier during anaerobic exercise such as sprinting or weightlifting [141]. Indeed, consumption of 6.4 g BA daily for four weeks has been shown to increase muscle carnosine levels by 64.2% [142]. Moreover, supplementation with BA for 4–10 weeks has been
shown to increase knee extension torque by up to 6% [143], improve workload and time to fatigue during high intensity cardio [144–148], improve muscle resistance to fatigue during strength training [149], increase lean mass by approximately 1 kg [147] and significantly
reduce perceptions of fatigue [150]. Additionally, the combination of BA and CM may increase performance of high intensity endurance exercise [151] and has been shown to increase lean mass and decrease body fat percentage more than CM alone [152]. However, not all studies have shown improvements in performance with BA supplementation [143, 153, 154]. To clarify these discrepancies, Hobson et al. [155] conducted a meta-analysis of 15 studies on BA supplementation and concluded that BA significantly increased C-X-C chemokine receptor type 7 (CXCR-7) exercise capacity and improved exercise performance on 60-240 s (ES = 0.665) and >240 s (ES = 0.368) exercise bouts. Although BA appears to improve exercise performance, the long-term safety of BA has only been partially explored. Currently, the only known side effect of BA is unpleasant symptoms of parasthesia reported after consumption of large dosages; however, this can be minimized through consumption of smaller dosages throughout the day [142]. While BA appears to be relatively safe in the short-term, the long-term safety is unknown. In cats, an addition of 5 percent BA to drinking water for 20 weeks has been shown to deplete taurine and result in damage to the brain; however, taurine is an essential amino acid for cats but not for humans and it is unknown if the smaller dosages consumed by humans could result in similar effects [156].