It's a Good Thing I Practiced Drinking in College -OR- Sweat Test
So. Looking for a sanity check and feedback on the very high numbers from my latest sweat test.
By very high numbers, I mean, I did the sweat test and was surprised to see a recommendation of 77-91 oz / hr to stay hydrated 
. I'm hoping you can provide a sanity check, check my math and thinking about implications for races this season (pretty please and thanks?)
Context:
I'm 6'2, 218 lbs at 18% bf, and usually sweat a lot during exercise. I did the sweat test on the trainer, with fan and ambient temperature at 65 degrees. I weighed in with one hour to go, dialed in a Z3 effort for 1 hour, and weighed myself after. I opted for Z3 since my first race this season is Quassy, followed by IMLP and rounding out with IMOO.
The Math:
Starting: 218.4 lbs (including the two PowerGels I consumed during the test)
Ending: 216.6 lbs
= (1.8 lbs) / hr
16 oz / lb X 1.8 lb / hr = 28.8 oz / hr (Lo)
24 oz / lb X 1.8 lb / hr = 43.2 oz / hr (Hi)
Add the two X 24 oz bottles of Gatorade consumed during the hour:
28.8 oz / hr + 48 oz / hr = 76.8 oz / hr (Lo)
43.2 oz / hr + 48 oz / hr = 91.2 oz / hr (Hi)
Ok. So that works out to 3.2 to 3.8 bottles of Gatorade. Per hour. Have I used the emoji yet? So I decided to compare this with my previous experience and do the pro / con thing.
In the "ok, this kind of makes sense" column:
- I usually try to take in 2 bottles of Gatorade (48 oz / hr ) on the bike. As far as I can recall, I've never had to pee off the bike. And I've always struggled with staying hydrated / fueled on the run. So, there's that.
- My body composition is heading downward at 1-2 lbs / week towards my target race weight of ~ 200 lbs for IMLP; when I'm at race weight, I notice my heat retention is noticeably less, and my sweat rate is lower. I assume I should re-test after Quassy at a Z2 effort and closer to race weight for more accurate numbers, and adjust accordingly for the full distance races this year - does that make sense?
- I tried the new hydration rate on the rides over the last two weeks. It took some effort, but I managed to work up to the 3.2 bottles / hr for the last four big rides, and even 3.8 bottles / hr on the 3.5 hr ride in 90 degree weather. Basically, I feel like being on the bike is playing a drinking game I suck at i.e. "oh look, squirrel" DRINK "change gears" DRINK "day that ends in 'y' " DRINK...
- Surprisingly, it was do-able, aside from feeling a bit burpy and sloshy, but I don't think I can maintain that rate for much more than 3-3.5 hrs.
- And... while it could be the consistent training or any number of factors, but I felt stronger on the bike, didn't have the fog roll in the way it usually does. And... I peed once each long ride, past the halfway mark towards two thirds milestone. Good volume, clear colour. On the way out, I think I may have even high-fived the next guy in line for the porto-potty.
- Taking that into consideration, I should look at the current sweat test as a 'high water mark' for the season, and expect lower numbers as the season progresses... yes?
In the "you've got to be kidding me" column:
- 3.2 to 3.8 bottles of Gatorade per hour is A. LOT. OF. JUICE. I must be bumping up against the upper limits of fluid / calorie / salt absorption. I get that there's some variation in rates, but seriously, I always hoped my superpower would be marketable, not the ability to imbibe big numbers. Remember dude who tried to consume nearly 3 lbs of apple sauce? Ya. I don't want to be that guy.
- 3.2 to 3.8 bottles of Gatorade Endurance is A. LOT. OF. CALORIES. Using the formula from the sweat test page, I should target between 500-550 cal/hr, depending on my weight (200-220 lbs). At 160 cal + 300 mg Na per bottle, I'm taking in 512- 608 cal / hr + 960-1,140 mg Na / hr.
- Add in the 2 PowerGels / hr (110 cal / 200 mg Na each) I'm taking in 732-828 cal / hr + 1,360-1,540 mg Na / hr. That seems like a lot. Can my body even really absorb that much?
- Between the torpedo, down-tube, and seat cages, I can carry four bottles on the bike (I try not to think about the extra 6 lbs of weight 
), which introduces some practical considerations. It gets messy, but reloading the torpedo 3 times in an hour is do-able; it's the trying to collect four bottles per aid station without crashing that makes me a bit nervous. Open to any feedback or suggestions here.,
- Open to any suggestions for fueling on the run - I prefer to ditch the Camelbak for races, but not sure how a higher hydration rate relying only on aid stations will work on the run... thoughts?
Long post, but hoping to find some sanity and plan.
Thanks in advance,
Evan
Comments
I'm sure you'll get several replies especially from folks more experienced then me but I'd say your math looks right and your in that category of being a heavy sweater and a larger athlete. To me the validation in reading your post is that you couldn't recall having to pee off the bike. I believe the EN guidance is that as a minimum you should have to pee twice during the IM bike let alone perhaps again when you get off the bike so I would say you've been under doing it previously. If you can pee while you bike there is no downside in my mind then of erring on the side of overdoing it to ensure you are fully hydrated when you get off the bike.
It sounds like you have a calorie target per hour and that the gatorade will get you there so you shouldn't need the gels and by your own math that puts you over your calorie target. Coach Patrick's guidance is after you get on your bike that you should be drinking (once your HR settles down) to the point where you are burping it back up and then settle into your plan consumption rate.
Its great to hear you have begun training with this level of hydration because it may take a little training of your gut to accomodate that volume and amount of calories. Being such a heavy sweater you may also want to evaluate your whole nutrition plan to ensure you are getting enough Na+ & K+ per hour. The EN nutrition calculator worksheet has been a good tool for me.
For what it is worth... I'm 170lbs and a heavy sweater and need at least 2 bottles an hour on the bike.
Re the aid stations, most are well before the 1 hour mark unless you are in the worst triathlon ever. So I start with 2 bottles and am at 1.5 by the 10 mile mark...where I grab one, maybe two more...and keep that up every 10 miles...two bottles an aid station is totally doable.
for the run, it's just 4oz of sports drink a mile. When running, you can't take in very much....so stick to that.