Quick Answer: Mild dehydration can impair mood and attention; rehydration helps. Moderate coffee isn’t dehydrating in habituated adults, but afternoon caffeine can harm sleep. If you’re foggy, start with fluids + electrolytes and keep caffeine earlier. Zhang 2019; Killer 2014; Drake 2013.
Who it helps
- Office AC + low water intake + long afternoon meetings.
How it works
- Dehydration → mood/cognition dips; rehydration improves them. Zhang 2019.
- Moderate coffee is not dehydrating in free‑living adults. Killer 2014.
How to use
- 12–20 oz fluid + electrolytes with lunch; cap caffeine by 2 pm.
7‑day plan
- Replace post‑lunch coffee with electrolytes; rate focus at 2 pm and sleep quality.
CTA
Keep hydration steady—Momentum pairs well with electrolytes for smooth energy.
