I am on week 2 of the minimal gear foundation. This week I am having a lot of pain in the knees right above the kneecap as I approach 90. I think I'm doing them correctly & I really like the workout. I don't want to mess up my knees & have to stop. Is there an alternative you would recommend to build up my knees? A step-back lung isn't as uncomfortable.

Hey James - it is hard to say exactly what the knee pain may be stemming from, but there is no need to go past 90. Stop the lunge just prior to the pain. Step ups are a great alternative and walking backwards on a treadmill can help strengthen your knees immensely. You should do the recommended PT here: https://lab.mtntough.com/rehab-and-prehab/season:2/videos/patellofemoral