When doing workouts like Merced +1 or vo2 intervals like Kern +1, i often find i can do 30 - 50 watts more than the prescribed power (i often tack on an extra interval too at the end of each set). Does this mean i naturally have a high vo2 max or is there a different reason.
For reference my ftp is 284 (60kg/134 pounds) and was recently tested 2 days ago with a ramp test where i did get the most out of myself. Any tips, advice or help is much appreciated.
Nice.
You know what to do… up the intensity
What’s the relationship between FTP and VO2 Max power? Sounds like you may have significant room to grow FTP…
What are you using to measure power? My thoughts are that some wheel-on trainers especially can over-report power at higher intensities due to the trainer/tyre warming up.
But you could equally just be a cyclist who has a high “top end” and either way you should feel free to adjust the intensity as @jacemano says 
My experience with the wheel on Kickr Snap for Over 2 years is that is not true at all. Compared to my Quarq PM the both tracked very closely. The trainer is warmed up for 10 mins of riding and then a spin down calibration is performed.
Just re-read my original message and agree it was a little damning on wheel on trainers…
This wasn’t intentional; there are plenty of good ones - just wanted to offer it up as a possible explanation.
I personally only had this issue with the tacx vortex and only really if i was too lazy to ride 15 mins before calibrating
Just for reference, I find sweet spot workouts based on my ftp to be torture. For the kind of riding I do, it would be nice if it was the other way around. I think it’s about muscle type and adaptation. I’m sure there is a disconnect between vo2max and ftp for some of us.
Anything less than 1 minute is okay. I really have trouble with 3 minute intervals. I can do 30 second intervals all day. One minute on/one minute off requires me to concentrate on my recovery.
Before I started TR, I found out that when I climbed a lot, my sprinting got a lot better. Climbing was still mediocre. Need to lose weight.
Not everyone has the same relationship between their MLSS and the strength of their anaerobic system.
So if the plan says “do these anaerobic intervals at 150% of FTP” for you that could be too much, could be too little.
You could bump up the intensity using the little plus sign, but IIRC that means everything bumps up, not just the interval. So if the work interval is too easy but the rest interval is just fine, use the workout creator to make your own version of the workout.
This advice is of course assuming that your FTP-based / zone 4 interval sessions are appropriately challenging (and not also too easy).
certainly nothing to worry about.
Also i just realized you said “anaerobic” in the title and then “vo2max” in the post, which i assume to mean intense (above MLSS) but still aerobic.
Are you finding both types of workouts too easy? Just one? Same general advice in the short term (bump it up) but the physiology driving each one would be a bit different.