Anaerobic Power + Static Strength

Training:

for time @ 70% (somewhat hard)
800m run
65 push-ups
rest 4 minutes
+
for time @ 80% (very hard)
800m run
45 push jerk - 40/25kg
rest 4 minutes
+
for time @ 90% (very very hard)
800m run
25 burpee pull-ups

Notes:

Somewhat hard = uncomfortable, but not the end of the world
Very hard = challenging to you, on the cusp of stopping
Very very hard = I could not repeat this effort within 24 hours

Hard is anything not easy.  Where is the line drawn between the two for you?