CFE

sounded easy enough...3 rounds (running or biking) of:

5 seconds on, 10 seconds off,
20 on, 10 off,
10 on, 10 off,
30 on, 10 off,
15 on, 10 off,
25 on, 10 off.

Since I stubbed my toe, I wanted to rest it and opted for biking. I rode the stationary bike at the depot set on level 12 and took off.

For something that was less than nine minutes of work...it was a brutal one! It was hard to keep the RPM >100 for the 30, 15, and 25 sets at the end and the 10 second rests seemed to get shorter each time.