I switched to Athletica.ai as my preferred training platform pretty much a year ago, and aside from a brief absence from the platform (after which I had to start pretty much from scratch) I’ve found it pretty good on the whole. Athletica seems to be well-rooted in the science of training, with a significant reliance on HIIT workouts. A typical workout schedule for me generally has one HIIT workout each week (shown below via intervals.icu below, click the image to enlarge).