Lol have you tried doing a plank for about a minute and a half? If you're not used to doing a plank, you'll feel like a minute is so long. Haha, I remember back then I used to be able to hold a plank for two minutes after I got used to it but then I stopped doing planks and now when I try it even a minute of it feels so long. Your core's gonna be really worked when you do this exercise.