Considering the fact that prof. I. Mirzai was an officer in the Iranian army and founder N. Rahmazadeh has trained commando troops in times of war, one may expect a tough fitness training; it can last half of the lesson, about 45 minutes.
There are people who attend class especially for the fitness training, among them also Dutch marines.
If you are in no good shape at all this will be no problem, because you only participate in teh activities you chose.
Fitness training is not only meant to prepare for the lesson to come, it contains more elements. Besides loosening up the body and letting the body get used to enduring physical activities it you also perform some exercises from power yoga, your courage is tested and you can have special 'rotation training'.
This means a lot of stretching exercises have a meditative character. 'Courage training' means doing exercises which in first sight seem scary (like leapfrogging over several human bucks), but aren't all that scary any more once you've done them. 'Rotation training' means many rotating exercises; in this manner you can test and enhance your ability to make controlled movements, despite dizzyness or even nausea. This can be practiced in kata or fighting.
The main theme in the fitness training is 'getting to know ones own body', 'finding your borders' and 'crossing your borders'.
The most extreme form is 'toughening up'. After the regular sit-ups, push-ups and the like the body is toughened up by means of punches and kicks on belly, back, arms en legs. Not only the body is toughened up, but also the mind. Ofcourse one of our general rules applies here too: everyone trains on his own level, and nothing is obliged.