3′ hard, 3′ min conversational, 4′ hard, 4′ conversational.

(3′) 22 @ 5k+8 then 22 @ 5K+12
(4′) 24@5k+6 then 24@5k+10
(5′) 26@5k+4 then 26@5k+8

then back down to 3 again.