If you want to combine your VO2 max training with more muscle-building activities, then find a HIIT (high-intensity interval training) program you like. There are endless combinations, usually involving bodyweight/lightweight exercises, often with some quick sprints through in. The goal is to do them all in quick succession until you’re totally beat. Squats and chest-presses are common components. You can even add in time on a bike or battle ropes if you’re fast enough. This article has a lot more info.