I set the countdown timer to 15 minutes. The exercise is a Navy SEAL burpee, but when I come up, I do it from an airsquad, and I add two extra air squads, for a total of 99 pushup and 99 airsquad movements. I'm working harder/faster at the beginning, and I end it with a plank exercise for more core strength.

x  = one Navy SEAL burpee combo
-- = one minute plank exercise

|15 |14 |13 |12 |11 |10 |9  |8  |7  |6  |5  |4  |3  |2  |1  |0
 xxx xxx xxx xxx xxx xx  xx  xx  xx  xx  xx  xx  xx  xx  --

source: exercise.md