Sprint Work

3 rounds
Sprint 400m (1:20; 1:29; 1:33)
Walk back 200m (3:00 rest)
Sprint 200m (0:37; 0:40; 0:41)
Walk back 100m (2:30 rest)
Sprint 100m (0:17; 0:17; 0:17)
(2:00 rest)