VO2 Max interval workout question

Fairly new swifter here with a question. I am doing the build me up program. I am a 56 YO woman and have been cycling for about 7 years but have never done structured training. I ride road, mountain and sometimes gravel.
My issue is that during my VO2 max workouts that call for 115% of VO2 max, my heart rate maxes out by the second of 5 intervals and the recovery does not seem nearly long enough. I know my FTP is accurate as all of the other training seems to be fine and I can complete it. Iโ€™m trying to understand the intent of the workout on my system so want to adjust it the right way.
So, should I just adjust the VO2 part down to a level , say 110% FTP where I can get through it and donโ€™t have to extend the rest period, or should I keep it at 115 and take the longer rest so I can keep doing the intervals at the higher power level? I also had an issue with the Neuromuscular interval that was 150% of FTP. I lowered that by 5% and was able to get through it. Thank you for your input.

Power at Vo2 max can vary quite a bit between people, generally between around 108% and 120%, so turning it down to 110% should still give the desired response. Any VO2 max intervals should feel really hard, but just about manageable :sweat_smile: