You go until you cannot complete the amount of pullups in the minute.
Ex. 1 pullup the first minute, 2 the second, 3 the third, so on.
Say you are on the 14th minute and you cannot complete all 14 pullups in that minute, then you are done.
Yes.
But if you come up short of 10 minutes -- reset until you hit 10 minutes. This is to make sure you do at least 10 sets.
Example:
1 - 1 pullup
2 - 2 pullups
3 - 3 pullups
4 - 4 pullups
5 - 3 pullups + Failure -
RESET TO ONE6 - 1 pullup
7 - 2 pullups
8 - 3 pullups
9 - 4 pullups
10 - 5 pullups
If you can go past 10 minutes without failing -- then by all means, continue...
I can go to like 13 or 14 or something like that last I tested -- but that was a LONG while ago.