The power in watts you can hold on the bike for roughly an hour. Over middle distance the target sits at around 70–78% of FTP as normalized power.
FTP turns \"how hard may I ride?\" into a number you can hold yourself to when adrenaline claims otherwise. Over 90 kilometres, coaches work with roughly 70 to 78 percent of FTP as normalized power; for first-timers and weaker runners the safe band sits nearer 70 to 72, for very strong runners up to 80 to 85. The expensive mistake doesn't happen at the end but in the first 30 to 45 minutes after the swim exit: if your meter already reads 82 percent instead of 74 after twenty minutes, the damage to your run is usually done. Write the target on your handlebars or watch instead of inventing it mid-race. What often gets missed: the value goes stale — use a test no older than eight to ten weeks. And without a power meter you translate it to heart rate or the talk test: full sentences have to be possible, not just single words.