Weight loss during Z2 outside ride

So I rode 2 hrs in Z2 and took on 48oz of fluid. Starting weight was 219.6 ending weight was 217.4. But…I stopped to pee twice. I use a low calorie hydration mix with 550mg sodium per 24oz. Think that I hydrated correctly? It was sunny and 68 degrees on the ride

Not sure I can answer the “did I hydrate correctly”
question directly, but those numbers seem very reasonable to me.

I recently performed a sweat test and in one hour lost 3lbs. Was a Z2 endurance ride indoors with no fan and drank nothing. Was 71 degrees with 39% humidity during this test.

Repeated the test a week or so later, but the temp in my garage was 77 with higher humidity and lost almost 6lbs!


Based on those slight tests how much liquid and sodium do you aim to get in per hour?

I’ve never had to pee on a 2hr ride. I suspect your body was already overhydrated and trying to ditch water before you started (fasting? low sodium intake?). So I suspect your starting weight was a bit inflated. The time get a bolus of salt was maybe an hour before the ride. Aside from the nature-break thing, I’ll commonly be short a 1lb or 2 of water when I get home, even on just a 2 hour z2 ride, no mater how much I tell myself I’m going to drink more.

Honestly I kinda threw the 2nd test out. It was pretty unreasonable to do that one without a fan in my opinion.

That said I pretty much stick with the 1 bottle
per hour. To be fair though I don’t really do “long” rides. 90% of my rides are TR 60 and 90 min workouts.

I’ll do something like SIS beta fuel or UCAN plus a 2nd bottle with just water on the 90 min rides (usually threshold intervals). For the 60 min intervals I just have a gel.

Seems like an awful lot of fluid for a two hour ride, perhaps evidenced by the need to pee twice!

It’s hard to tell without knowing how your sodium and water levels were before you started. If your sodium in blood is on low side, the body will dump extra water to try and keep the blood sodium concentration in the correct range.

Of course this is all individual, but on my hardest 3-6hr rides I take in at least 2 bottles per hour. And I have a bottle before I start. On shorter or easier rides, I’ll stick to 1 bottle per hour. I recently drank 7 bottles in a 3hr ride, didn’t pee during and didn’t pee until 4-5hrs after the ride.

Most rides I return and barely lose any weight. What I’d recommend is take a ride you do often and try it multiple times with different hydration plans. If you are currently hitting a wall, you will know if increasing hydration helps.