Quadriceps Muscle

During the exercise intervention "Death by Squats", which compasses body weight squats until maximum exertion, 25-30 subjects shall be tested for heart rate, the oxygen saturation of the vastus medialis and the triceps, resting and at maximum exertion blood lactate, as well as the rate of perceived exertion on the borg scale. At the end, all should indicate their primary reason for stopping (local fatigue, systemic fatigue, time constraints, motivational deficit).