Creatine supplementation prevents acute strength loss induced by concurrent exercise.

PURPOSE: To investigate the effect of creatine (CR) supplementation on the acute interference induced by aerobic exercise on subsequent maximum dynamic strength (1RM) and strength endurance (SE, total number of repetitions) performance. METHODS: Thirty-two recreationally strength-trained men were submitted to a graded exercise test to determine maximal oxygen consumption (VO2max: 41.56 ± 5.24 ml kg(-1) min(-1)), anaerobic threshold velocity (ATv: 8.3 ± 1.18 km h(-1)), and baseline performance (control) on the 1RM and SE (4 × 80 % 1RM to failure) tests. After the control tests, participants were randomly assigned to either a CR (20 g day(-1) for 7 days followed by 5 g day(-1) throughout the study) or a placebo (PL-dextrose) group, and then completed 4 experimental sessions, consisting of a 5-km run on a treadmill either continuously (90 % ATv) or intermittently (1:1 min at vVO2max) followed by either a leg- or bench-press SE/1RM test. RESULTS: CR was able to maintain the leg-press SE performance after the intermittent aerobic exercise when compared with C (p > 0.05). On the other hand, the PL group showed a significant decrease in leg-press SE (p ≤ 0.05). CR supplementation significantly increased bench-press SE after both aerobic exercise modes, while the bench-press SE was not affected by either mode of aerobic exercise in the PL group. Although small increases in 1RM were observed after either continuous (bench press and leg press) or intermittent (bench press) aerobic exercise in the CR group, they were within the range of variability of the measurement. The PL group only maintained their 1RM. CONCLUSIONS: In conclusion, the acute interference effect on strength performance observed in concurrent exercise may be counteracted by CR supplementation.

Análise do desempenho em atletas de elite no "Ironman" Brasil entre os anos de 2003 a 2010 / Performance analysis of elite Brazil-Ironman athletes from 2003 to 2010

O objetivo do presente estudo foi analisar a evolução no desempenho no "Ironman" Brasil entre os anos de 2003 a 2010. Adicionalmente, verificamos qual modalidade apresentou maior influência sobre o desempenho final na prova. Foram analisados os 10 primeiros colocados da categoria elite masculino de cada ano avaliado. As diferenças entre os tempos foram analisadas por ANOVA, seguida por "post-hoc" de Tukey. O coeficiente de correlação de Pearson foi empregado para investigar a associação entre o desempenho total e o desempenho nas diferentes modalidades isoladas. Os resultados mostraram não ter havido evolução no desempenho ao longo dos anos, sendo observada grande variação nos resultados. Foi observada, ainda, correlação entre o tempo de prova no ciclismo e o tempo total (r = 0,82; p < 0,01), sendo que o atleta com melhor tempo no ciclismo foi, também, o campeão da prova em 75% das vezes. Por fim, concluímos que não houve evolução no desempenho ao longo dos anos analisados. Adicionalmente, o ciclismo parece ser a modalidade determinante para o sucesso do atleta no "Ironman" Brasil.

The aim of this study was to analyze the performance evolution on the Brazil-Ironman from 2003 to 2010. Additionally, we verified which of the modalities were the most influential on the overall performance. The first ten athletes for each year in the ELITE male category were analyzed. The differences between the racing times were analyzed by ANOVA, followed by Tukey post-hoc test. Pearson's correlation coefficient was utilized to investigate the association between races performance and the performance in each one of the different modalities. The results showed that there was no performance evolution over the years and a great variation in racing times was observed. We have found a important correlation between cycling performance and race time (r = 0.82; p < 0.01) and the fastest athlete in cycling was the Brazil-Ironman champion in 75% of the analyzed years. Thus, it was concluded that there was no evolution in race time over the analyzed years. Additionally, the cycling might be the most influential modality for athletes' success in Brazil-Ironman.