Effects of 7-day polyphenol powder supplementation on cycling performance and lung function in an ozone-polluted environment

The Effects of Polyphenol Supplementation on BDNF, Cytokines and Cognition in Trained Male Cyclists following Acute Ozone Exposure during High-Intensity Cycling

The neurotoxic effects of ozone exposure are related to neuroinflammation and increases in reactive oxygen species (ROS). This study aimed to assess inflammation, Brain-Derived Neurotrophic Factor (BDNF), and cognition in healthy male cyclists following polyphenol supplementation and exercise in an ozone-polluted environment. Ten male cyclists initially completed a maximal incremental test and maximal effort 4 km time trial in ambient air. Cyclists then completed two trials in an ozone-polluted environment (0.25 ppm) following 7 days of supplementation with either polyphenol (POLY) or placebo (PL). Experimental trials consisted of a three-stage submaximal test followed by a 4 km time trial. Blood samples were drawn pre- and post-exercise, and analyzed for BDNF, interleukin 6 (IL-6), interleukin 10 (IL-10) and tumor necrosis factor (TNF-α). The Stroop test and serial subtraction task were performed before ozone exposure and again after the 4 km TT. Serum BDNF increased post-exercise (p < 0.0001), and positive differences were observed post-exercise in the ozone POLY group relative to PL (p = 0.013). Plasma IL-6 increased post-exercise (p = 0.0015), and TNF-α increased post-ozone exposure (p = 0.0018). There were no differences in Stroop or serial subtraction tasks pre- or post-exercise. Exercise increases BDNF in ozone.

Cranberry supplementation improves physiological markers of performance in trained runners

PURPOSE

Cranberries have the highest polyphenol and antioxidant capacity among fruits and vegetables and may protect against exercise-induced free radical production, consequently improving performance. This study aimed to investigate the effect of polyphenol-rich cranberry extract (CE) on time-trial performance and lactate response following exercise.

METHODS

A total of 14 trained runners were tested at i) baseline, ii) 2 h following an acute CE dose (0.7 g/kg of body mass), and iii) 4 weeks after daily supplement consumption (0.3 g/kg of body mass). At each time point, runners performed a 1500-m race followed by a 400-m race where the live vastus lateralis oxygenation changes were determined by near-infrared spectroscopy and blood lactate was measured at rest and 1 and 3 min after each trial. The Shapiro-Wilk test and repeated-measures analysis of variance were used to establish significance (P <0.05).

RESULTS

Cranberry supplementation over 28 d improved aerobic performance during the 1500-m time trial, whereas the acute dose had no effect. More specifically, muscle reoxygenation rates were significantly faster after 28 d compared to baseline (P = 0.04; η² = 0.29), and a trend towards slower deoxygenation rate was observed (P = 0.13; η² = 0.20). Chronic CE consumption also buffered the post-exercise lactate response for the 400-m race (P = 0.01; η² = 0.27), while no effects were seen for the longer race.

CONCLUSION

Our results suggest that cranberry supplementation may have ergogenic effects, as it improves physiological markers of performance during short- and long-distance running.