Works: glutes, hamstrings, quads, triceps, biceps, lats and shoulders, abs and core.
Seagull: while in elbow plank stretch your arm forward, then turn it 90 degrees to the side.
Elbow lifts: lie on the floor, preferably on something soft, and push off using your elbows (not your arms) – you should feel the tension in your back. The exercise hits lats the same way pull-ups do so it’s perfectly normal if you find it hard to do. Try to lift your whole body off the floor – your torso and glutes, but if you can’t, just lifting your torso will suffice.