Fatigue at certain points of the game or training is related, among other factors, to the high concentration of H+ in the muscle which can limit the ability of muscle contraction. Thus, any intervention that can reduce the rate of intracellular H+ accumulation during high intensity exercise would increase performance.
Physiological role of β-alanine
Carnosine is a cytoplasmic dipeptide found in skeletal muscles and in the central nervous system. One of the physiological effects of carnosine is to buffer H+. Muscle carnosine is formed by bonding histidine and beta (β)-alanine and previous studies have shown an increase in muscle carnosine concentration after long term β-alanine supplementation.
In a recent study, Sale et al. (2011) from the Nottingham Trent University, UK, had their subjects perform an anaerobic test before and after 4 weeks of either β-alanine supplementation (6.4 gr/day) or placebo intake. Their results showed a 16% improvement in performance during the anaerobic test that lasted 150 sec. Although this is different to what happens in football we can assume that β-alanine supplementation may enhance anaerobic performance in football players.
To my knowledge there is only one study using a football specific protocol (repeated sprints on the treadmill). In this study, physically active men performed 2 sets of 5x5-sec sprints with 45sec recovery after 5 weeks of β-alanine supplementation (Sweeney et al., 2010). Their results showed no effect of β-alanine supplementation on repeated sprints abillity.
The findings of these studies seem contradictory. To my point of view this is not the case. From these and other studies in the literature it seems that β-alanine supplementation may enhance performance during exercise bouts that stress lactic acid production and lactic acid accumulation. When exercise, as in the case of the study by Sweeney et al. (2010) above, does not result in high lactate and thus H+ accumulation β-alanine has no effect on performance. No doubt that more research, in particular on football players is needed before reach a conclusion.
One more point. There is strong evidence that β-alanine supplementation a) reduces body fat, and b) increases muscle strength. Both effects have applications to football training and performance.
What is the effective strategy?
The effective protocol seems to be the ingestion of 6.4 gr/day β-alanine for 4 weeks. Tablets should be consumed at 4 equal doses at 3 to 4 hours intervals.