Difficulty level: 3
Plank is great not only for the abs, but for your whole body. You can do plank on your forearms, as shown on the picture (this is the easier way) or a classic plank on the palms. The recommended time to hold this position is one minute.
Difficulty level: 1
You can do this exercises as a warm-up for buttocks and legs: lean against a chair and do several sets of 15-20 squats for each leg.
Difficulty level: 2
The lower the squats, the harder they are to do. For starters, you can squat on something like a couch, but only if you touch it a little, without actually sitting down on it. Keep your back straight and your knees should be directly over your ankles. Do 20 squats in one set, choose the number of sets depending on how you feel.