Strength training lying down without aids

When you are ready to start your strength training without aids, there are three exercises which you can do.
The first exercise we have here is the pelvic lift where you bend your legs under yourself in bed and lift your pelvis as high as you can.
You can do three of these. And then you can repeat.
The next one we have is the leg lift where you stretch your legs out in bed and alternate lifting the one leg and then the other leg as high as you can.
And you can repeat this depending on how many you think you can do. 
And the last one we can do here in bed is an abdominal exercise where you do sit-ups, so you lift your torso as far up in bed as possible.
And it should tighten in the stomach. And you can do three or four and then take a break and then do it again.
And these are the exercises you can do in bed which are for strength training without aids.