So rarely will Coach Jack push you close to failure. We believe failure based efforts are better to do as your own personal dynamic training. Do 4 1 minute intervals as hard as you can for example and on the last one go until you can’t do any more. Ideally outside when it feels amazing.
You have to remember FTP (CP) and W’ are semi-independent and improve differently. So normally you start a season with base or lower intensity and right before a race or some time when you are ready to hit peak performance you do much higher intensity. The end being this “peak” period. During this peak period, you might want to stress yourself to the maximum. If you are doing VO2max workouts, in a perfect world you would design each one specifically to take your W’bal lower and lower until after about 4 weeks you are starting to fail the workouts. Coach Jack does not do this so you would have to do this yourself. You could take a single day a week of your peak block from CJ workout and design it for yourself.
Coach Jack is not about killing yourself with difficulty although you can crank up the sliders and make it super hard. This is more for the guys that love math and want to test their personal limits and see how accurate the math is or see if the math helps inspire them to go harder.
In a perfect world if you really want to go this heavy math route of training like this then getting more accurate CP and W’ you would use a 20 minute test for CP/FTP tests and use a 2 or 3 minute slope mode all out max effort to test your W’.
So I would ignore Coach Jack and W’. Our workout editor is more for the people that want to design their own workouts. Now over time I am happy to continue to try to add to your education that Coach Jack can just be an additional tool in designing part of your season.
It’s hard because there are many different mainstream ideas on how to train and they compete with each other a bit. Trying to maximize TSS is and designing everything around that is common and really does not make sense and proven it does not make sense yet it is still popular. It does not mean you can’t get faster but it’s just less efficient energy wise in the long term and comes with higher risk of burnout. High amounts of energy required and the benefits long term are not better. Now TSS/CTL/TSB/ATL are very useful and since you seem to be interested you should understand them as well…