October 2012

Accredited Sports Dietitian Christine Dziedzic shares her experience of attending the 17th annual congress of the European College of Sport Science (ECSS) held in Bruges, Belgium in July this year. Here is her summary of two sessions that she attended…

Dr Wim Derave from Ghent University (Belgium) presented an update from the 2011 Carnosine Congress on the ergogenic potential of beta-alanine. It is the rate-limiting precursor for the synthesis of carnosine in muscle and its use is increasing in the sporting community. Chronic daily ingestion of beta-alanine has been shown to markedly elevate muscle carnosine levels, which has been associated with improved exercise capacity, particularly in sports that include high-intensity episodes. Despite initial thoughts that carnosine acts as a pH-buffer, Dr Derave suggested that an increase in carnosine content may enhance calcium sensitivity in the muscle, and in this way help the muscle to become fatigue resistant. Dr Derave considered the need for supplementation protocols to be corrected for body mass. A 3.2 g dose of beta-alanine taken daily for seven weeks resulted in a 20-30% increase in muscle carnosine content in those who weighed greater than 80 kg and up to 80% in those weighing less than 60 kg. The safety of chronic supplementation remains unknown.

Christine’s take-home hint: consume beta-alanine with meals; there may be a role for insulin in the uptake to the muscle (similar to creatine). For more information – see the special supplement of Amino Acids, 2012, 43(1) (http://link.springer.com/journal/726/43/1/page/1).

Dr Joanna Bowtell from Exeter University (UK) presented as part of the ‘Sports Nutrition from Mother Earth’ symposium, sponsored by Gatorade. Discussion surrounded the functions of flavonoids and anthocyanins, found in berries and cherries (along with other fruit and vegetables), namely vasodilatation. Dr Bowtell reminded us that these phytochemicals are poorly bioavailable and therefore not likely to have a direct antioxidant function, but rather they may enhance endogenous antioxidant capacity. Montmorency cherries (sour) are particularly rich in anthocyanins and possess anti-inflammatory properties as well. Dr Bowtell’s research has shown that consumption of cherry juice prior to and following intensive exercise suppressed measures of oxidative damage and improved acute muscle strength recovery (back to 91% of baseline after 24 hours). Research with other fruits, such as blueberries and pomegranate are showing similar results. There is some concern with chronic use to ‘support’ training, as the active components may block reactive oxygen species (ROS) signalling, and in fact dampen exercise adaptation. This suggests current application be kept to acute doses and short-term use.

Christine’s take-home hint: while the optimal dose is unknown, Dr Bowtell aims for ~600 mg polyphenols (65-70 ml Montmorency cherry juice concentrate), twice a day in the three days leading up to, and throughout early stages of intensified training or competition.

For more information – Bowtell, et al. (2011). Montmorency cherry juice reduces muscle damage caused by intensive strength exercise, Med Sci Sports Exerc, 43(8), 1544-51. 

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