Middle distance interval:
3 x 10 minutes
Rest: 3 minutes

#1. 20 (+18), 22 (+16), 24 (+14), 26 (+12)
#2. 22 (+14), 24 (+12), 26 (+10), 28 (+8)
#3. 22 (+16), 24 (+14), 26 (+12), 28 (+10)

cool down