ECSS Paris 2023: OP-PN14
INTRODUCTION: Athletes engaged in precision sports often experience extended and varying short-wavelength visible blue light (SBL) exposure during training and competition. As a result, it may negatively impact the athlete’s visual function and overall performance. Current data have shown that the dietary eye carotenoid (lutein (L), zeaxanthin (Z), meso-zeaxanthin (MZ)) along with omega-3 dietary fatty acids (ω3) enhance visual performance in healthy eye (free of retinal disease) populations, but this has yet to be tested in athletes. The Sport Nutrition Intervention in Performance Exercise (SNIPE) study is a randomised, double-blind, placebo-controlled trial aimed at investigating the impact of a supplement containing L, Z, MZ with ω3 over a 9-month period on vision and sport performance among Singapore shooting and archery athletes. METHODS: A total of 51 shooting and archery athletes, with a mean (±SD) age of 28 (± 8.01) years, took part in this study. The active group received a supplement containing L, Z, MZ + ω3, while the placebo contained sunflower oil. Carotenoid status was assessed by measuring blood serum L, Z and MZ concentration (S-L, Z, MZ levels) as well as skin carotenoid concentrations (SCS). Visual function was evaluated by measuring visual acuity (VA) and contrast sensitivity (CS) at 6 and 12 cycles per degree (cpd) under both photopic and mesopic conditions for the dominant eye. Subjective visual function was evaluated with the VF questionnaire (VFQ). Sport performance was measured by recording shooting score (SS) and total aiming time (TAT) for every 10-shot intervals, up to 60 shots, during simulated competitions. RESULTS: Statistically significant difference with large effect size was observed in the active group for time-over-treatment interaction effect on carotenoid status (SCS and S-L, Z, MZ levels p <0.001 for all, η2 for SCS = 0.209 and S-L, Z, MZ= 0.276, 0.305, and 0.320, respectively), dominant eye CS at 6 cpd under mesopic conditions (p=0.008, η2 = 0.141) , and score for last 50 shots (p = 0.019, η2 = 0.112), last 60 shots (p = 0.046, η2 = 0.082) and total of 60 shots (p = 0.047, η2 = 0.081), in comparison to the placebo group for both sports. No significant differences were observed for TAT, VA, and VFQ (p>0.05 for all, η2 for TAT=0.010, VA=0.002, VFQ=0.000). CONCLUSION: The findings above, which indicate improvements in sporting performance among archers and shooters following carotenoid and omega-3 enrichment, are novel and likely attributable to the optical and antioxidant properties of these dietary carotenoids.
Read CV Parimala SivaperumanECSS Paris 2023: OP-PN14
INTRODUCTION: Caffeine, which can modulate physiological and perceptual responses and improve exercise performance, is widely used in intermittent high-intensity sport. In applied settings such as team sports and tournament play, athletes often perform multiple high-intensity bouts separated by prolonged recovery, creating uncertainty regarding optimal caffeine supplementation strategies. It remains unclear whether a single pre-exercise caffeine dose maintains ergogenic and physiological effects when high-intensity exercise is repeatedly performed. Clarifying this would provide valuable insights into strategies to maximise caffeine's ergogenic effects. This study examined whether a single dose of caffeine (6 mg/kg) sustains repeated-sprint cycling performance up to 3 h post-ingestion and assessed the associated plasma noradrenaline, ventilatory, cardiovascular, and cerebral haemodynamic responses. METHODS: Twelve healthy adults (4 females) completed randomised, double-blind, placebo-controlled, crossover trials following caffeine (6 mg/kg) or placebo ingestion. At 60, 120, and 180 min post-ingestion, participants performed 5 min moderate-intensity cycling (50% heart rate reserve) followed by repeated sprinting (6 x 5 s). Plasma samples were collected repeatedly for caffeine and noradrenaline analysis. Middle cerebral artery mean blood velocity (MCAVmean) was measured via transcranial Doppler, and common and internal carotid artery blood flow were assessed at rest using ultrasound. Respiratory and cardiovascular variables, ratings of perceived exertion (RPE), and leg muscle pain were recorded. RESULTS: Plasma caffeine concentrations increased by 30 min post-ingestion and remained elevated throughout the protocol. Caffeine increased peak and mean sprint power output compared with placebo across all sprint sets performed at 1, 2, and 3 h post-ingestion, with peak power enhanced by up to 3.8%. These performance benefits were accompanied by attenuated perceptual strain, including lower RPE and reduced leg muscle pain. During sprint exercise, plasma noradrenaline concentrations were higher with caffeine from the first to the final sprint set. MCAVmean was lower with caffeine throughout the protocol, coinciding with reductions in end-tidal partial pressure of CO2 and resting common and internal carotid artery blood flow. CONCLUSION: A single pre-exercise ingestion of 6 mg/kg caffeine enhances repeated-sprint ability for at least 3 h post-ingestion. These findings suggest a single dose provides sustained ergogenic effects for repeated sprinting without additional caffeine. Prolonged effects on plasma noradrenaline, cerebral blood flow, and perceptual responses were also observed, and these effects may contribute to the aforementioned enhanced performance, although direct investigation is warranted. We show that a pre-exercise intake of 6 mg/kg caffeine improves sprint performance and modulates sympathetic cardiorespiratory and perceptual responses during prolonged intermittent exercise over 3 h.
Read CV Mizuki NishikawaECSS Paris 2023: OP-PN14