The 30 day challenges.

A bit of ab training won't hurt as summer is coming up. In the past I've tried doing ab exercises, but I always simply forget to do them and then gave up in less than a week. And yesterday I say this picture passing by on Facebook:

So after googling I found more different photos like this too. Some with the same schedule, some a bit different.

Source.

And then other 30 day challenges appeared too. For instance this arm challenge:

Source.

Or how about the squat challenge:

Source.

I love the idea of these as they may help me remember doing the exercises! Perhaps it's even be best to print one out, stick it to a wall and cross off the days. The issue I have with these however is this: how do you keep up the results once the challenge is over? Maybe, do the Day 30 exercise trice a week? Or more frequently?

I'll try and find one for abs that I like and start somewhere in the next few days and I'm curious whether it's doable and effective!
Sincerely,
R.