Abs workout

As a person who doesn't go to the gym because I'm lazy, I usually do 2 exercices for abs workout. 

Doing the plank is pretty easy and challenging at the same time. 

Mountain climber is more efficient but also way harder because it's a very tiring exercice. But the most important is to not give up and to make sure working out becomes a habit. You don't always need to go to the gym to workout.