Run 25' on a hilly course or treadmill. Let the HR get up to high Z3/low Z4 on the uphill and keep HR in Zone 1-2 otherwise. Stretch when done and add in Core 1, 2 or 3.
WU: 200 warm up (wu). 8 x 50 on 15 sec rest.
MS: 500 yd TT (time trial) for time.