[Alun]

i've attended one of Sebastien's clinics. here's my input...

you should aim to keep your training very specific for best results (true for all sports). if you want to dive deep then do an exhale static followed by a dynamic, both of approximately equal duration, and go for maximum distance, or close to it.

if i remember correctly i think he told us that he achieved his highest levels of hematocrit by doing laps and laps of exhale dynamics. after some time he decided to change his training routine by doing just one maximum in each session. his performances continued to improve despite the fact his hematocrit had returned to relatively normal levels. you can either train for 'bout diving' (lots of shallow dives) by doing laps and laps or you can train for max depth by doing one max each session. i think this is why he changed his routine - he wanted to train for max depth. it makes sense.

... so although raised hematocrit will improve performance in general, the situation is obviously more complicated than that. i.e. it's not as simple as just boosting your hematocrit. you have to train your whole body (and mind!) to dive in this way. so i wouldnt focus on maximising your hematocrit as your ultimate goal (unless that really is your goal!). i would do exhale static/dynamic sets that are appropriate for your goals... i.e. lots of sub-maximal laps for bout diving or a single max per session for max depth.