Of course, you know your body better than we do. But here's the deal. Integral Strength builds up from three days of training per week to six days per week—that's a pretty intense strength program.
Layering another program on top of that might cause overuse injuries, and it would likely cut into your recovery time, which will slow your progress and leave you vulnerable to injury.
If you want to get the best results from Integral Strength, we recommend focusing on it for the duration of the program and then cycling to work on your next goal once you're done. Read more about the benefits of cycling your training here.