Drinking while doing tri's

For running, are you using on-course water stops, with the paper cups?

No, I'm carrying a small water bottle with gatorade that clips to my hands. It seemed like using the course cups didn't work so well for me.

My only suggestion would be little drinks. This way you can swallow in between breaths and it doesn't take away from getting oxygen in your system. Keeping hydrated and enough nutrition in longer races is very important so I would suggest slowing sown to get your fluid and calories on race day. Hope this helps.

OK. Well, either way, with running, you have to slow down a bit. I'm far more experienced with the cups, so I can relate what I do there. I pinch the top of the cup closed, slow my pace and shorten my stride and take short, quick sips. I hold the liquid in my mouth until a natural point to swallow, then repeat.

Either way, it takes practice.

I think you need to slow down enough on the bike that you can drink reasonably from your aero bottle.  Unless you have some kind of swallowing disfunction, that's just way too hard.    Maybe I am wrong, but that seems to me anyway.

I have been known to wear a Camelbak on the bike, too.   I did that to minimize the need for reaching, etc, and to carry enough fluid for a half iron distance race.  But it's very easy to drink from.  But if you're not willing to slow enough to drink, you might find putting on the backpack in T1 to be a problem.  ...

For running, the cups take practice.  I will slow to a walk so I can get it down, it only takes a few seconds.   But, there have been MANY races where I have carried a hand held bottle.    It seems to me that the very fast runner basically throw it down their throat in one toss.  Where you are in that continuum you will need to figure out

Have you tried the hard hat that holds two beers with straws? Be careful, biking drunk is not safe, and the pounding of running may pop one of the beers out.