For the first two breaths of the POWERbreathe K series device are setup breaths so that the device can calculate correct parameters for your training. The setup breaths have a low load setting of 3cmH20 and therefore you will find the first two breaths very easy to overcome. For breaths 3 and 4 a gradual load set to 50% and 75% of your maximum training load is introduced. Subsequent breaths are set at 100% of your maximum training load.