After a 10-minute warm up at a low intensity, the intensity goes up by 25 Watts every minute. You just keep pushing for as long as possible. Take 75% of the last minute that you completed, because that should correspond with your FTP. Set your FTP at 250W first if you do this test indoors using the ERG-mode of your trainer. In this test there is no cool down included, but we recommend to cool down for at least 10 minutes after the test at 50-60% of your FTP to recover.