Yes a forceful exhale, but there are different things folks do to inhale. Most newbies try to get in a full breath, like they would running or cycling, so unmetered breathing. In swimming it is quite important to get you head back down ASAP and I see too many taking too long to get that full breath in. I played around with it a lot over the years, and found that even just a super quick inhale pretty much fills the lungs. And I can tell that from the exhale, as it seems almost the same as if you held your head up and gulped a full one.
And as waverider pointed out, sometimes you can even hold it for just a bit, but of course he is quite advanced and a front pack pro swimmer type. And yes distance swimmers do have a bit more time to get it all done, but it still is an imperative to get it done with proper timing. And I also learned the floatation thing, but as I said earlier, Gary Hall seems to think getting all that air out in the down position is also a benefit as it releases tension on the water to have those bubbles travel down the center of your body…
I have not heard of this, but this is an interesting idea. Does Hall cite any evidence or info (scientific, anecdotal, or otherwise) that he knows of that shows/indicates/proves that exhalation air and/or bubbles running down one’s centerline underwater decreases drag?
I watched a video he did on this, and if you think about it, it has some merit I believe. We try so hard to get bubbles off the hand so that we can get a 100% grip on the water. And we know that aerated water has much less purchase, so makes sense if you have air under your body, it has less drag in the water..
He really looks at the tiniest science for swimming, and seems to come up with many of the newer developments that eventually become mainstream. I would love one day to get down to one of his camps, imagine there is a lot of free speed I could gain from his findings…