4 ms·
Not a direct answer, but I've found this helpful: http://www.swimsmooth.com/exhalation.html http://www.swimsmooth.com/exhalation.html
by chillax 9y ago
Not a direct answer, but I've found this helpful: http://www.swimsmooth.com/exhalation.html http://www.swimsmooth.com/exhalation.html