Complete as many round of the following as possible in 25 minutes.
With a continuously running clock do one pull-up the first minute, two pull-ups the second minute, three pull-ups the third minute…
continuing as long as you are able
When you can no longer match the round, reset the cycle to 1 pull-up the next minute and continue until the 25 minutes has expired.
You may have to reset multiple times during this workout. All pull-ups are to be done strict.