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.
Use as many sets each minute as needed.

Here's the 4:30 Foundations Crew.  From L to R, Jasmine, Terri, Rebecca, and Jason.  Solid group with solid efforts!

Here's the 4:30 Foundations Crew. From L to R, Jasmine, Terri, Rebecca, and Jason. Solid group with solid efforts!