Effects of conventional and sugar-free energy drinks intake in runners: a double-blind, randomized, placebo-controlled crossover clinical trial.

BACKGROUND: This study evaluated the effects of two types of energy drinks (ED) intake in trained runners. METHODS: A double-blind randomized placebo-controlled clinical trial was conducted over 6 weeks. Participants and beverages were allocated by randomization. Twelve men 23±2.6 years, 177±3.4 cm, 74.4±5.5 kg, VO2max=59.8±5.5 mL·(kg.min)-1] ingested either a conventional energy drink containing carbohydrates and 3 mg·kg-1 of caffeine, (ED1), a sugar-free energy drink 3 mg·kg-1 of caffeine (ED2), or a carbohydrate-containing, decaffeinated placebo (PL) 40-minutes before an exercise protocol. Sprint time, rate of perceived exertion (RPE), respiratory exchange ratio (RER), blood pressure (BP), heart rate and plasmatic glucose were evaluated during the experimental protocol. RESULTS: Performance improved after consuming both ED (P<0.004 ED1 and P=0.001 ED2) with lower RPE (P<0.05 for ED1 and P<0.05 for ED2) compared to PL. Consumption of ED2 decreased RER values at 0-5 minutes and 40-45 minutes (P<0.001), and ED1 increased systolic BP (P<0.05) during exercise compared to PL. There were no differences in the evaluated parameters between EDs (P>0.05). CONCLUSIONS: Consumption of conventional or sugar free ED represents a valid ergogenic strategy to improve acute performance with reduction of RPE. However, intake of a conventional ED warrants caution, mainly because the effects on systolic BP.

Association between the number of daily steps and the cardiovascular risk factors in basic education teachers.

BACKGROUND: Regular physical activity is suggested as an important non-pharmacological mechanism to prevent cardiovascular diseases. Thus, the objective the present study was to verify the association of the number of daily steps with cardiovascular risk factors in basic education teachers and analyze the suitability of the cutoff of 10,000 steps/day as a predictor for the main risk factors in this sample. METHODS: Two hundred teachers (43.2±10.2 years) of basic education were assessed in Viçosa, Brazil. It was analyzed the number of daily steps, Body Mass Index (BMI), waist circumference (WC), waist-hip ratio, body fat percentage (%BF), systolic and diastolic blood pressure, glucose, total cholesterol, high-density (HDL-C) and low-density lipoprotein cholesterol, non-HDL cholesterol and triglycerides. RESULTS: The group which exceeded the 10,000 steps had lower BMI, BF% and triglycerides (P<0.05) compared to those who did not reach this value. A weak inverse correlation between the number of steps and BMI, WC and %BF was observed. Overweight and dyslipidemia were significantly associated with low number of steps (<10,000). The average number of daily steps was predictive of major cardiovascular risk factors, with the best cutoff near the 8000 steps for the presented results. CONCLUSIONS: Basic education teachers who exceed the 10,000 daily steps have a lower BMI, %BF and triglycerides. On the other hand, teachers who do not overcome show a greater chance of overweight and dyslipidemia. The cutoff point of 8000 steps/day in this sample had an appropriate value in the prediction of the risk factors analyzed.