When I started, I thought 30 seconds was a long time. I kept doing them, and they got longer. I try to do two a day, and aim for 3:00+.Wow! That's more than most people can do. I can do about 2
Here's a tip: Do a plank when you're pissed off at something. (Like the news on the TV!) Channel that pissed offedness into physical energy.