The 5 most important exercises for the straight abdominal muscles

Effective exercises for the straight abdominal muscles are:

Crunches with angled legs Starting position is lying on the back. The legs are lifted off the floor, creating a 90 degree angle in the hip and knee joint. The arms are crossed behind the head and the upper body is lifted from the floor and guided towards the knees.
The head should be held as an extension of the spine to avoid additional strain on the neck.
Sit-Ups The design is very similar to the crunches. The feet are placed on the floor and the upper body lies flat on the floor. Now, in contrast to the crunch, the entire upper body is lifted and brought into the upright sitting position.
This is a complete touchdown.
Forearm support The forearm support is a good stability exercise for the straight abdominal muscles. It also strengthens the back and other torso muscles.
Folding knife The folding knife is another very effective exercise for the abdominal muscles. By simultaneously lifting the legs and the upper body, the entire straight abdominal muscles are trained simultaneously.
Abdominal wheel Another exercise is the abdominal wheel, which also trains the straight abdominal muscles. Kneeling on the floor, you start to stretch and bend your body with a wheel. The fitter the abdominal muscles are, the further forward you can bring your arms with the wheel.

The 3 most important exercises for the lower abdominal muscles

Athletes who focus on the lower straight abdominal muscles should not omit the following exercises:

Leg lifting while lying down The starting position is lying on the back. The arms are at the sides of the body or are stretched upwards over the head. Now the outstretched legs are lifted off the floor and brought up to a vertical position.
At the highest point, the movement is reversed and the legs are slowly and in a controlled manner guided down and held just above the floor. There the exercise starts all over again. The upper body should rest calmly on the floor during the exercise.
Sit-ups on the negative bench The upper body is lower than the legs.
The legs or feet are fixed in the holding device and the upper body is guided upwards as far as possible in the direction of the knees/legs. At the uppermost point, the movement is reversed and the upper body is guided back towards the bench. At the lowest point, the upper body is not laid down completely, but held and started again.
Reverse Crunches Starting position is lying on your back with your arms bent so that your fingers touch your head.
The legs are also raised and the knees are close to the head. The lower legs are approximately parallel to the floor. Now the upper body is lifted and as close as possible with the nose to the knees. At the same time the knees are moved even closer to the head. At the end point the tension is held for a short moment to reverse the movement afterwards.