there goes experimental science for you ! I can make a nearly dead thread take a gasping breath ! I can hold breath for swimming underwater a pool and a half-ish, depends if I do not use too much energy turning around at the end of the line.
How long is the 'pool', and how fast do you swim? This doesn't tell us much. Although it does sound quite impressive regardless. I doubt I could swim a pool and a half above water, breathing.
the pool is standard 50m and I go slow, maximizing the use of each push momentum, following the bottom . And the last seconds are agonizingly long, fighting between the increasingly demanding urge to surface and the waning will to continue just one more push... just one more push...
The first time I tried I took a really big breath and got 45 seconds. After that I waited a few minutes and tried again, but with a slightly smaller breath. This time I got to 1 minute and 38 seconds. Perhaps I could've gone further but it really didn't feel right and hadn't done so for a while so I just ended it.
