From a true exercise nerd: This sounds like fun.

But the math sounds off a bit.

If you did 50 burpees in 20 minutes, that's 2 1/2 burpees a minute. I don't see how you can do a burpee slow enough to take more than 20 seconds to do one. I just tried to do a burpee in 20 seconds and to do it that slow was quite difficult.

And you said David Goggins advocates 100 burpees in under 10 minutes That's about 5 seconds per burpee.

The person in the photo (who, of course, is not including a pushup) is doing a burpee in about 3 seconds.

And without warming up, I just did 12 burpees (including pushups) in 1 minute (I said I was an exercise nerd; I don't deny I do stupid things like trying 12 burpees without warming up - especially stupid since I'm a few months shy of 70:>)

Are you sure it took you that long? My guess is maybe you might be able to do a lot more if you check again... or my arithmetic is much worse than i thought!