I mentioned David Goggins as an inspiration in one of my recent instagram posts. He is truly hardcore.
I started doing a workout that he recommended called nickels and dimes- sets of 5 pull ups and 10 push ups, every minute for 15 minutes minimum. I've been doing about 20 minutes, getting to 100 pull ups and 200 push ups, keeping focused on good form throughout. Working to an hour with no breaks. Here I am today after 5 miles of interval sprints and then nickel and dimes- worked but energized!
Here are some links to what David Goggins is all about:
and the full article: