How long should an effective ab workout be?

As long as it takes to finish. Why do autists ask this question as if takin an extra 2 minutes for their sit ups will make their abs suddenly pop?

However long it takes you to do front squats.

>>41215589
kek

>>41215581
You can literally walk around all day doing vacuums.

File: 1403606992266.jpg (21KB, 500x500px) Image search: [Google]

21KB, 500x500px

You know damn well /fit/ doesn´t isolate abs, silly buns

fucking a cum fuck

>>41215613
I do weighted decline sit-ups every once in awhile

Does taking a big shit work your core? Asking for a friend.

I'll do 20-30 minutes of ab variations 3x a week.

>>41215647
Yes but don't forget to do negative reps as well for maximal gains.

An ab workout should be 90 minutes according to my friend but i think that its a bit too much

>>41215687
Your friend has no idea what he's talking about. He literally made up a number.