Obviously TS thought the pump is the muscle he build during the workout session.

"Curl 15 reps, wah my biceps growing leh walaoweh!"
Then
"I curl more I grow faster"
Then a few day rest
"Eh die liao my biceps shrinking, I must curl again"
Then probably turn into unnecessary supplement like casein protein to avoid muscle lost, 1 scoop before sleep, every 2 hours must supply the biceps with protein so it don't shrink, BCAA la bla bla bla.
or
"Eh I'm not growing anymore, I need mass gainer!"

All above happens in 1 month time.