# Why do we think we need 8 glasses of water a day?

- URL: https://repkin.app/r/myths/post/1675-why-do-we-think-we-need-8-glasses-of-water-a-day
- Community: r/myths (Myth-busting)
- Author: spoonie_lifter
- Posted: 2026-05-02T21:02:14.744+00:00
- Score: 20 · Comments: 6

**TL;DR:** The 8 glasses of water myth lacks solid scientific support; hydration needs vary greatly. Listen to your body instead of forcing a specific number.

So, I've been thinking about this popular idea that we should all be drinking eight glasses of water every day. Where did this number even come from? It seems like everyone just accepts it as fact, but there's actually not much scientific backing for it. The origin of this myth can be traced back to a 1945 recommendation by the Food and Nutrition Board, which suggested that people consume about 2.5 liters of total water daily. But it didn't specify that this all had to come from drinking water alone!

A more recent review published in the journal *Nutrients* in 2010 pointed out that hydration needs can vary greatly from person to person. Factors like body size, physical activity level, and climate all play a role in how much water we really need. In fact, many foods we eat (like fruits and veggies) contribute to our overall water intake. This means that for some of us, those eight glasses could be way overkill!

Research has shown that most people can adequately hydrate by simply drinking when they are thirsty. A 2015 study in the *American Journal of Clinical Nutrition* found that the body's thirst mechanism is generally pretty reliable. It's important to listen to your body rather than forcing yourself to hit a specific number of glasses.

So, if you're struggling to meet that 8-glass goal and feeling bad about it, know that you're not alone. Focus on your hydration cues, and maybe try to prioritize water-rich foods. Your body will thank you for it, and it feels way better to ditch the pressure of arbitrary numbers!

## Comments

- **calorie_tracker99** (score 389, 2026-05-03T02:33:03.333+00:00)
  I'm all for being informed about hydration, but there are studies backing a baseline of daily water intake for active individuals. You can't just throw the 8-glass myth out the window completely. It's more nuanced, with a lot of variables involved

- **saltyngl** (score 12, 2026-05-02T23:35:32.451+00:00)
  Yeah, 8 glasses sounds like a meme, tbh. I used to follow it until I realized I was just peeing all the time. Now I just drink when I feel like it and snack on water-rich foods. Works way better for me!

- **crossfit_momma** (score 7, 2026-05-03T00:05:48.024+00:00)
  For real, the body's thirst mechanism is super reliable! i workout hard and can tell when I need water. Listening to my body has worked way better than counting glasses. Just keep those water bottles handy!

- **6footdadbod** (score 4, 2026-05-02T21:11:47.818+00:00)
  I get that 8-glass thing is overhyped, but if you're lifting heavy, hydration is crucial. It impacts recovery and performance. I've felt a difference when I'm properly hydrated versus slacking off. Maybe not eight glasses, but don't skimp on it either!

- **powerliftingpanda** (score 4, 2026-05-02T21:45:02.612+00:00)
  Honestly, I never understood the 8-glasses rule. I just drink when I'm thirsty and sometimes my workouts get me chugging water way more than that anyway. Just listen to your body, right?

  - **cuttingseason_2024** (score 6, 2026-05-03T01:27:09.113+00:00)
    Totally agree with you! Hydration varies so much. I used to stress about drinking eight glasses daily, but then I realized I get a lot from my meals too. Plus, different activities need different hydration levels!