Your FTP might be the Problem.
Want to hold your "target power " in your next Ironman triathlon? Let's talk about the FTP or Functional Threshold Power Test. This is a 20 minute time trial of all-out cycling, which for many triathletes is their only performance indicator when it comes to training and racing. But have you ever wondered if this really tells the whole story?
For some athletes, this test works well and closely estimated your true threshold. However, this isn't true for everyone.
If you struggle to hold your power in an Ironman or half Ironman, a falsely elevated FTP may be the problem. Your functional threshold power includes both anaerobic and aerobic energy sources. If you are an athlete with a high glycolytic capacity, the 20 minute FTP test will always give you a number that is 5-10% above your true threshold. This also creates some challenges with efficiency for the Ironman since lactate levels will likely be high.