Hypoxic = a shortage of oxygen, so for our purposes = breath control

BEGINNER WORKOUT:

200 easy swim (warm-up)

200 free pull

4×50 free taking only 5 breaths per 50 on the 2:00

8×25 free taking only 3 breaths per 25 on the 1:00

200 easy swim (cool down)

= 1000

INTERMEDIATE WORKOUT:

400 easy swim (warm-up)

400 free pull

400 free kick

4×100 free breathing every 5 strokes on the 2:30

400 easy swim (cool down)

= 2000

ADVANCED WORKOUT:

500 easy swim (warm-up)

500 free pull

500 free kick

10×50 free taking only 4 breaths

20×25 free (odd 25s no breather/even 25s easy) on the :30

4×50 free pull on the 1:00

4×50 (25 underwater travel no breather with fins/25 free sprint taking only 1 breath) on the 1:30

200 easy swim (cool down)

= 3100