Creatine but not betaine supplementation increases muscle phosphorylcreatine content and strength performance.

We aimed to investigate the role of betaine supplementation on muscle phosphorylcreatine (PCr) content and strength performance in untrained subjects. Additionally, we compared the ergogenic and physiological responses to betaine versus creatine supplementation. Finally, we also tested the possible additive effects of creatine and betaine supplementation. This was a double-blind, randomized, placebo-controlled study. Subjects were assigned to receive betaine (BET; 2 g/day), creatine (CR; 20 g/day), betaine plus creatine (BET+CR; 2+20 g/day, respectively) or placebo (PL). At baseline and after 10 days of supplementation, we assessed muscle strength and power, muscle PCr content, and body composition. The CR and BET+CR groups presented greater increase in muscle PCr content than PL (p=0.004 and p=0.006, respectively). PCr content was comparable between BET versus PL (p=0.78) and CR versus BET+CR (p=0.99). CR and BET+CR presented greater muscle power output than PL in the squat exercise following supplementation (p=0.003 and p=0.041, respectively). Similarly, bench press average power was significantly greater for the CR-supplemented groups. CR and BET+CR groups also showed significant pre- to post-test increase in 1-RM squat and bench press (CR: p=0.027 and p<0.0001; BET+CR: p=0.03 and p<0.0001 for upper- and lower-body assessments, respectively) No significant differences for 1-RM strength and power were observed between BET versus PL and CR versus BET+CR. Body composition did not differ between the groups. In conclusion, we reported that betaine supplementation does not augment muscle PCr content. Furthermore, we showed that betaine supplementation combined or not with creatine supplementation does not affect strength and power performance in untrained subjects.

Beta-alanine (Carnosyn™) supplementation in elderly subjects (60-80 years): effects on muscle carnosine content and physical capacity.

The aim of this study was to investigate the effects of beta-alanine supplementation on exercise capacity and the muscle carnosine content in elderly subjects. Eighteen healthy elderly subjects (60-80 years, 10 female and 4 male) were randomly assigned to receive either beta-alanine (BA, n=12) or placebo (PL, n=6) for 12 weeks. The BA group received 3.2 g of beta-alanine per day (2×800 mg sustained-release Carnosyn™ tablets, given 2 times per day). The PL group received 2× (2×800 mg) of a matched placebo. At baseline (PRE) and after 12 weeks (POST-12) of supplementation, assessments were made of the muscle carnosine content, anaerobic exercise capacity, muscle function, quality of life, physical activity and food intake. A significant increase in the muscle carnosine content of the gastrocnemius muscle was shown in the BA group (+85.4%) when compared with the PL group (+7.2%) (p=0.004; ES: 1.21). The time-to-exhaustion in the constant-load submaximal test (i.e., TLIM) was significantly improved (p=0.05; ES: 1.71) in the BA group (+36.5%) versus the PL group (+8.6%). Similarly, time-to-exhaustion in the incremental test was also significantly increased (p=0.04; ES 1.03) following beta-alanine supplementation (+12.2%) when compared with placebo (+0.1%). Significant positive correlations were also shown between the relative change in the muscle carnosine content and the relative change in the time-to-exhaustion in the TLIM test (r=0.62; p=0.01) and in the incremental test (r=0.48; p=0.02). In summary, the current data indicate for the first time, that beta-alanine supplementation is effective in increasing the muscle carnosine content in healthy elderly subjects, with subsequent improvement in their exercise capacity.

The effect of carbohydrate mouth rinse on maximal strength and strength endurance.

It has been previously reported that carbohydrate (CHO) mouth rinse can improve exercise performance. The proposed mechanism involves increased activation of brain regions believed to be responsible for reward/motivation and motor control. Since strength-related performance is affected by central drive to the muscles, it seems reasonable to hypothesize that the positive CNS response to oral CHO sensing may counteract the inhibitory input from the muscle afferent pathways minimizing the drop in the central drive. The purpose of the current study was to test if CHO mouth rinse affects maximum strength and strength endurance performance. Twelve recreationally strength-trained healthy males (age 24.08 ± 2.99 years; height 178.09 ± 6.70 cm; weight 78.67 ± 8.17 kg) took part in the study. All of the tests were performed in the morning, after an 8 h overnight fasting. Subjects were submitted to a maximum strength test (1-RM) and a strength endurance test (six sets until failure at 70% of 1-RM), in separate days under three different experimental conditions (CHO mouth rinse, placebo-PLA mouth rinse and control-CON) in a randomized crossover design. The CHO mouth rinse (25 ml) occurred before every attempt in the 1-RM test, and before every set in the endurance strength test. Blood glucose and lactate were measured immediately before and 5 min post-tests. There were no significant differences in 1-RM between experimental conditions (CHO 101 ± 7.2 kg; PLA 101 ± 7.4 kg; CON 101 ± 7.2 kg; p = 0.98). Furthermore, there were no significance between trial differences in the number of repetitions performed in each set (p = 0.99) or the total exercise volume (number of repetitions × load lifted [kg]) (p = 0.98). A main effect for time (p < 0.0001) in blood lactate concentration was observed in both tests (1-RM and strength endurance). Blood glucose concentration did not differ between conditions. In conclusion, CHO mouth rinse does not affect maximum strength or strength endurance performance.

Cálcio e a regulação da adiposidade e do peso corporal / Calcium and the regulation of adiposity and body weight

Obesity is known to be an evolving pandemic and adequate nutrition is one of the major cornerstones of its treatment and prevention. However, not only the role of energy partitioning and macronutrient distribution, but also the influence of micronutrients on the control of body weight and adiposity have been recently discussed. In this regard, calcium has received a great deal of attention by the scientific community. Several studies using both animal and human models (observational and randomly controlled trials) have focused on the effects of calcium on obesity, showing controversial results. Several factors seem to influence the results obtained, and although a definite conclusion is still unclear, the literature points towards an interesting positive effect of the increased intake of dietary calcium (particularly from dairy sources) on the regulation of body weight and adiposity in the overweight and obese population undergoing restrictive energy intake.

Se sabe que la obesidad es una pandemia en evolución. La dieta adecuada se ha constituido en uno de los pilares para su tratamiento y prevención.Sin embargo, recientemente, se ha discutido no sólo el papel de la restricción calórica y distribución de macronutrientes, sino, también, la influencia de los micronutrientes sobre el control del peso corporal y la adiposidad. En este sentido, el calcio ha recibido una atención especialpor parte de la comunidad científica. Diversos estudios, tanto los realizados con animales como con seres humanos, en ensayos clínicosaleatorizados y en modelos observacionales, se han centrado en esta temática, con resultados controvertidos. Varios factores parecen influiren los resultados obtenidos, y, aunque no haya una conclusión definitiva sobre el tema, la literatura señala un interesante efecto beneficiosoen el aumento de la ingesta de calcio (especialmente cuando proviene de los lácteos) sobre el control de la adiposidad y del peso corporal deindividuos con sobrepeso y obesidad sometidos a la dieta restrictiva.

A obesidade é, sabidamente, uma pandemia em evolução. A dieta adequada tem se constituído em um dos pilares no seu tratamento e na suaprevenção. Contudo, recentemente, tem sido discutido o papel não só da restrição calórica e da distribuição dos macronutrientes, mas, também, a influência dos micronutrientes sobre o controle da adiposidade e do peso corporal. Neste sentido, o cálcio tem recebido especial atenção da comunidade científica. Diversos estudos ? tanto com modelo animal quanto a partir da experimentação com humanos em modelos observacionais e em estudos clínicos controlados ? têm se debruçado sobre esta temática, com resultados controversos. Vários fatores parecem influenciar os resultados obtidos e, embora uma conclusão definitiva acerca do tema ainda não seja clara, a literatura aponta para um interessante efeito benéfico do aumentodo consumo de cálcio dietético (principalmente quando oriundo dos laticínios) sobre o controle da adiposidade e do peso corporal de indivíduoscom sobrepeso e obesidade submetidos à dieta restritiva.