How dehydrated does one get on a 1/2 IM swim?
325
Member
1693 days
jeslol posted 3 years ago.
Depends on how much of the lake/ocean you drink while you're swimming :o) I did a 1/2IM swim as part of a relay last fall...didn't really notice dehydration too bad. However, I did drink quite a bit of the lake on the way back. The beauty of the bike is that you can have a picnic while you ride...eat, drink and get ready to run.
2334
Member
2426 days
Tribro posted 3 years ago.
I think weather conditions and wetsuits can factor into it as well, so it's hard to say exactly, You shouldn't need as much as you would in bike and run as it's less likely you'll perspire especially if you keep your heart that low.
Obviously you can't apply the practice of taking in liquids every 15-20 minutes as you would on the bike or run, so I'd be sure you get enough fluids the day before, the morning of, prior to the start, and post swim.
478
Member
1474 days
kona_expat posted 3 years ago.
In any race less than IM distance, your pre-race hydration should take you through the swim easily. It's natural to feel like you want to drink right after you finish the swim; after all, in practice you don't swim the straight distance that often. If you swim in salt water, you probably want that post-swim drink even more.
Do your pre-race hydration, try this out in training, and then also drink 8-16 oz. sports drink about 1/2 hour before your swim and see how that works.
When you do exit the swim in a race, resist the temptation to drink anything until you've been on the bike 10-15 min. Why? Because your body is busy trying to get blood circulating to your lower extremities, and if you complicate things by putting something into your stomach that needs to be processed, you are slowing down the transition from swimming to biking. At 10 or 15 minutes into your ride, resume your normal drinking schedule.
Now in an IM, it's possible (depending on how long the swim takes you) that you do actually become a little bit dehydrated during the swim, but the same rules apply. No drinking on the bike until 10-15 min. have passed to let your body adjust to cycling.
Something else that might be at work here is that you are actually overhydrating, and have become used to that drink right after you finish swimming. Unless you have another workout right after you swim, for even up to a 1 hour swim, you can practice "waiting" 15 minutes after you are done to drink. Sometimes what you really want is to just rinse out your mouth. That's natural after soaking in chlorine! But trust me, if your overall hydration status is good heading into a 1 hour swim, and it's not at all-out speed, you should be fine coming out and not need to drink immediately.
I am doing my first half IM on 4/3/05. I have come to realize that it is going to take me at least 45 minutes to do the swim. While my average hr for a swim of this length is only about 118-120, I come out of the water pretty thirsty. I know I can drink in T1, but am I already going to be behind on hydration when I start the bike? Any tips?
John
“A man who says it can’t be done is generally interrupted by someone doing it.”