[Homie]

dude, i'm a crossfiter come on...
.
20 reps my ass

lets do like this,
do
like this, with 100 kg bw total
(it means u will have to add weight on ur skinny body)

10 rounds
in 7 minutes
of
5 pull ups
10 push ups
15 squats

or try this one in less then 3:12 (thats my time after 45 minutes of practicing pc)
deadlift 140 kg 9 reps
60 meters sprint
deadlift 140 kg 6 reps
60 meters sprint
deadlift 140 kg 3 reps
60 meters sprint

and that are some examples of the last to trains...

and 20 reps in the gym? they should fire in charges of wasting people time