i have been doing intervals training 3x3 4x4 5x5. i went for a cycling triathlon 40k using them. i cycled as fast as i can in the first 20k which i noticed my heart rate is very fast. then for the next 20k my heart rate is normal. is this a good performance. i do not have any figures only using what i feel.
my body is very hard in the 1st 20km and feel more relaxed in the last 20km.
i know there is a up and down in my performance, fast slow fast slow experience. 10 minutes fast then slow down. is this a good performance or should i do sommething else.
You don't have any information on split times, pacing, glances at your speedometer to see how the first and second 20K compared in terms of performance?
Split times and course conditions including wind would tell a lot, but from what you posted it sure looks like you went out too hard and faded in the second half. Your HR almost certainly dropped because your intensity dropped and your speed dropped. If your power had stayed the same for the first and second halves of the race you'd expect your HR to stay high and even drift slowly upwards over the course of a 40K TT.
Folks just don't get negative HR drift (HR dropping) during a long steady paced effort, if the HR dropped noticeably, then your power must have dropped substantially.
So why the diet of short VO2 Max intervals? Do you do, or have you done more traditional 15 to 30 minute Threshold efforts like the classic 2x20 Threshold intervals in your training? Those are more directly applicable to a triathlete or someone riding 40K TTs. Sure the VO2 Max work can tune up the top end after building solid fitness with longer efforts, but it's not clear that you've done those longer efforts in your training. In addition to the specific fitness they'll build they should teach you to pace longer efforts to help you avoid going out too hard and fading.
