Support the weight of the trunk with the elbow, which should be vertically aligned and at the same height as the shoulder, and the knee.

1. Raise the upper leg and hips, up to the shoulder, hip and knee remain fully aligned to form a straight parallel line with the ground. 

2. Maintain this position for 20-30 seconds. 

3. Rest, switch sides and return to the starting position. 

4. Repeat with side against the lateral. 

5. Repeat the exercise three times.