How much water needed on marathon long runs?

I don't know if you are trolling about the Camelbak or not.

Last summer I did about 7 or 8 runs of 20-23 miles, mostly in the very early morning when it was coolest. I would start off south on the trail, out and back about 6 miles. I would then grab a 0.5L (16.9 ounces) bottle of Gatorade out of my car and carry it with me north on the trail, out and back 14-17 miles. This would be enough for me to stay hydrated. I would be pretty thirsty by the time I got done so I had more Gatorade in a cooler in my car. Everyone's hydration needs vary (Salazar was legendary for sweat loss) so you might need more but I would think 32 ounces with 20 ounces waiting for you at the end should be plenty.

Do you live in Alaska, Arizona, Maine, Florida, ... ? Hydration needs vary wildly by location, by season, and by person.

This is true. I was training in Colorado at 6000' so humidity was not a factor. Big difference training in 80 degrees in COS and 80 degrees in Miami.

I honestly didn't know what that thing was; I do want one though.

I appreciate the post, no sarcasm. I am just seeing where I could have improved my training from the last time and know I need to get better at hydration.

Appreciate the post!

I honestly think a bit more water, better diet and more mileage will get me 3:20 or better. Boston is still a few Marathons away though...

Learning to slow down my EZ pace so I can have tons of mileage safely (60-70 this year, vs. 35-38 mpw like normal marathon/half-marathon base weeks).

Central Ohio, 900 feet above sea level. A bit humid in the summer but NOTHING like the Midwest!

You really need to get some sense of how much you sweat, it varies a huge amount from one individual to another. In warm weather a range of 0.8 liters to 1.5 liters per hour is sometimes used to express how much athletes sweat but even more is possible. You don’t have to replace 100 percent of losses just enough to avoid suffering negative dehydration impact. If you go with a vest make sure your okay having the tube over your shoulder. I bought one but prefer using 2 bottles in the front, the kind that collapse. Shop around for vests - brands like Salomon, Nathan, and Ultimate Direction might work better than Camelback

Thank you! Naperville is a nice area. I love Chicago and want to run the Chicago Marathon someday.

I will shop around. Nathan's handheld has worked well for me since 2017.

If you ran 3:24 with 37 mpw you should be aiming for closer to 3:00 with 60-70 than

You don't need any water on marathon training runs. Just hydrate after and you'll be fine. I do up to 21 miles (last 5 at tempo) without water in fairly warm weather. If it's dangerously hot, hydrating won't help and you probably shouldn't be working out hard anyway.

I never drank when I ran unless it was really hot.

Alain Mimoun won the Olympic marathon without drinking a sip of water.

Might what to check a book called - Waterlogged . by Noakes

On my 20 milers I never took anything. Started in the early AM.

I am pretty sure most of my long runs were done without water. If you hydrate a lot prior you'll be just fine.

I routinely put in 2.5 hour 22+ mile long runs without a lick of water in the summer. Really just depends on the route. If water is available I'll take it, usually by running near a park or gas station.

Alan

That being said.....I NEVER did a long Ruck March without a camelback.

A 12+ mile ruck with 40lbs is a lot harder than a 12 mile run in terms of losing water IF you are rucking for speed and shuffling at 10-11min miles.

During the BATAAN Death March Memorial Ruck that camelback was filled up multiple times.

Alan

Maybe ~5-8oz every 5k and/or 1 gel every 6k-10k.

Packs are fine or a loop where you can keep running by bottles might be better so you don't have to carry anything.

jecht wrote:

I honestly didn't know what that thing was; I do want one though.

I appreciate the post, no sarcasm. I am just seeing where I could have improved my training from the last time and know I need to get better at hydration.

Appreciate the post!

I honestly think a bit more water, better diet and more mileage will get me 3:20 or better. Boston is still a few Marathons away though...

Learning to slow down my EZ pace so I can have tons of mileage safely (60-70 this year, vs. 35-38 mpw like normal marathon/half-marathon base weeks).

You might need to drink a little more water in your marathons.

But since you mentioned kidney stones we have to start there.

What you really need is to work on your diet. Less meat and more water drinking everyday.

Gu every mile. 4 oz water with Gu. One HEED every fourth mile instead of the Gu.

https://www.hammernutrition.com/blog/heed-the-superior-sports-drink

As others have noted, it depends a great deal on weather conditions. Also, the most important thing is not starting in a dehydrated state. If you get on top of your drinking during the entire day, the run won't matter that much. If you're dehydrated to start, that could be a 60 oz deficit. Nothing you can drink on a run will make up for that. Keep in mind that the maximum rate of absorption during exercise is not nearly high enough to replace the water that you're losing. So at best, you're bending the curve slightly. The good news is that you can become significantly dehydrated before performance is adversely affected. Most elite marathoners don't actually take all that much water when they run.

For me, personally, I never carry water unless I'm doing some monster trail run in the summer (a rare occurrence). I will stop at a drinking fountain if it's convenient. It's only an issue for me in extreme conditions (20 miles at 90+ degrees). And I've never had any significant water in a marathon. My PR is 2:28, and at MP, I find that I can't take more than a single swallow at each aid station without getting stomach pains. Usually I just skip it.

32 oz during a run sounds like way too much. I know everyone is different but on a 20 miler I drink about 2-3oz with nuun at about mile 12.

If you think hydration is an issue, it may actually be an issue of salt/mineral loss. Your body may be telling you to drink in an attempt to replenish minerals but in reality you'll never replace your loses in a short time frame with only water.

Or you can try chewing gum to prevent dry mouth which has an illusion of dehydration.