Dose caffeinated energy drink is a consideration issue for endurance performance.

Caffeinated energy drinks are commonly taken to improve exercise performance, but there are few studies on the influence of different doses on an athlete's performance. We conducted a double-blind, randomized, counter-balanced, and crossover research study to examine the effects of low caffeinated energy drink (Low ED) or high caffeinated energy drink (High ED) supplement on the performance, haematological response, and oxidative stress in triathletes. Twelve male participants underwent three testing sessions separated by weekly intervals, consisting of sprint triathlon training (0.75 km swim, 20 km cycle, and 5 km run). Before and during the trials, participants were randomly provided with either placebo (PLA) group, Low ED group, or High ED group. Exercise performance in the High ED group decreased significantly compared with the PLA and Low ED groups (p < 0.05). However, participants in the Low ED group also experienced an improved performance (p = 0.054). Analysis of variance revealed no differences among the three groups in cortisol and testosterone levels, or the Borg Rating of Perceived Exertion score (p > 0.5). Furthermore, superoxide dismutase (SOD) was reduced with exercise and were lowest in the High ED group. However, compared with PLA, a significant decrease of thiobarbituric acid reactive substances (TBARS) was observed in Low ED and High ED groups (p < 0.05). This indicates that caffeinated energy drink consumption may improve performance and reduce oxidative stress in sprint triathlon athletes. However, individual differences should be considered when supplementing with caffeinated energy drinks to decrease side effects.

The role of DHEA-S in the mood adjustment against negative competition outcome in golfers.

Several lines of evidence suggest that dehydroepiandrosterone sulphate (DHEA-S) is invariably consumed following different types of acute stress, implicating its role in stress coping and recovery. The role of DHEA-S in the mood adjustment against negative outcome for athletic competition has not previously been investigated. In the current study, 14 elite golfers participating in a major national golf tournament were subsequently divided into two groups according to their competition outcomes: made the cut (n=8) and failed to make the cut (n 8). The Profile of Mood States (POMS) inventory and plasma concentrations of DHEA-S and cortisol were measured 1 day before the beginning of competition (baseline) and 1, 3, and 5 days after the players' final competition, in the morning (08.00-08.30 h) under fasted conditions. Results showed that the total mood disturbance scores and DHEA-S were not changed for the group that made the cut throughout the entire observation period. DHEA-S concentration for the group that failed to make the cut fell significantly below baseline values on day 1 and remained lower for 5 days. The Depression subscale of the POMS for the group that failed to make the cut was increased only on day 1 post-competition, reflecting a situational reaction to the event. Cortisol concentration for the group that made the cut fell significantly below baseline values on day 1 only after competition and no change was observed for the group that failed to make the cut. In conclusion, although the overall mood state post-competition was well-maintained for those golfers who had a negative competition outcome, plasma DHEA-S concentration was reduced for 5 days, suggesting that it has a role in the coping mechanism against psychological challenge.

Aging effects on glycemic control and inflammation for politicians in Taiwan.

UNLABELLED: Insulin sensitivity is deteriorating with age leading to many metabolic complications, yet fasting glucose is the common metabolic predictor in preventive medicine. In this study we compared the differences in fasting glucose, glucose tolerance, and inflammatory markers between two generations in politically active families. Their physical activity levels and dietary intake amounts were also evaluated. Eight elected councilors and their first order descendents participated in this study. Oral glucose tolerance test (OGTT), insulin, triglyceride, cholesterol, and inflammatory markers including C-reactive protein (CRP) and interleukin-6 (IL-6) were determined. Fasting glucose concentration in politicians was smaller than 100 mg/dL (considered clinically normal), and only approximately 14% concentration difference was observed between two generations. However, all politicians were substantially insulin resistant, compared with their young descendents, evidenced by exaggerated glucose and insulin responses (>100% greater area under curves above baseline) under oral glucose challenged condition. Their waist circumference, diastolic blood pressure, and cholesterol levels were significantly greater than controls. Furthermore, CRP of the politicians was approximately 2.3 folds of the control value suggesting a low grade inflammation. The levels of physical activity and dietary intake were not different between groups. However, the weekly walking energy expenditure for the politician group was approximately 3 times greater than that of the control. CONCLUSION: To reflect the age-dependent metabolic deterioration for the purpose of prevention, OGTT and CRP are far more sensitive measures than fasting glucose value. Greater walking activity in politicians was not sufficient to counterbalance the age-dependent changes.