Is the traditional 8-minute all-out effort test to determine FTP truly the most effective way to establish a baseline for the Zwift FTP builder, or would a shorter, more intense test - such as a series of 2-3 minute max sprints separated by short recovery periods - provide a more accurate representation of an individuals true functional threshold power? Some coaches and riders swear by the latter method, citing the fact that it better simulates the demands of real-world racing and reduces the risk of cardiovascular system fatigue, but others argue that the longer, more sustained effort of the traditional test is essential for fully taxing the energy systems. Whats the general consensus here - do we really need to go all-in for 8 minutes to get an accurate FTP reading, or can we get away with something shorter and more intense?