Progression I:
Adjust the sling trainer to a long length, take a stepping position with your back facing the sling trainer, hold the handles with your hands (overhand grip) and stretch your arms forwards, move your body forwards/downwards like a push-up and return to the starting position (bend and stretch your arms).

Progression II:
Analogue to progression I, but with feet parallel (slightly wider than shoulder width).

Progression III:
Analogue to progression II, but with one leg stretched out to the side (not touching the floor). After half the repetitions/time, change the supporting leg (possibly organisation = 2 exercises, train both sides).

Progression IV:
Analogue to progression II, but at a steeper angle (the closer the upper body is to the floor, the more challenging).

Attention:
Keep body tension, do not let hips sag, elbows bent approx. 45 degrees from the upper body ("A" shape with the arms), shoulders are fixed and pushed down towards the hips (for all progressions).

Harden:
The more horizontal the starting position, the more challenging the exercise.