Daily PubMed Research Digest — June 28, 2026

1. Nutrition: sugarcane polyphenols under heat stress

• Sample: 14 participants completed a double-blind, placebo-controlled crossover trial during 2 hours of running in hot conditions after 14 days of a polyphenol-rich sugarcane extract beverage/gel or matched placebo. 1
• Core finding: the extract condition had a lower IL-8 rise and lower average exercise-associated gastrointestinal symptom severity, but the trial also reported higher rectal temperature and physiological strain. 1
• Practical takeaway: treat this as an early signal for gut-stress management in hot endurance sessions, not as proof that athletes should add it on race day.

2. Exercise science: caffeine gum before resistance priming

• Sample: 15 male basketball players completed three randomized, double-blind, placebo-controlled crossover conditions: placebo plus resistance priming, 3 mg/kg caffeine gum plus resistance priming, and 6 mg/kg caffeine gum plus resistance priming. 2
• Core finding: both caffeine doses were associated with better 1-hour isometric strength, explosive power, sprint, and reactive-agility outcomes versus placebo, with no clear added advantage at 24 or 48 hours. 2
• Practical takeaway: if caffeine gum helps, this study points to a same-day window after priming; it does not show a next-day performance carryover.

3. Sleep research: adding sleep time in short-sleeping children

• Sample: 66 typically developing children aged 8-11 years who slept 9.5 hours or less per night were randomized to a behavioral sleep-extension intervention or usual sleep; sleep duration was measured with wrist actigraphy. 3
• Core finding: the randomized groups did not differ significantly in overall, physical, or psychosocial health-related quality of life over time, but children who increased sleep by at least 30 minutes per night reported higher quality-of-life scores in post-hoc analyses. 3
• Practical takeaway: for short-sleeping kids, the practical target is modest and measurable: see whether the routine can reliably add about half an hour of sleep.