Perform 20 seconds of max rep burpees, followed by 10 seconds of rest, continuously for 4 minutes i.e . 8 sets of 20 sec on/10sec off.
2. Interval runs
Perform 3 x 800m runs with a 3 minute rest between each run. Keep the stop watch running from the start of the first run until the end of the last run (including the 3 minute rests).