It's gonna be difficult to extremely difficult to do that consistently over an entire surgical residency. It'll especially be tough early on when you have the bulk of the call.
There will be windows where you have lighter rotations with more clinic time and less difficult cases/call where it will be easier to accomplish. Later on when you're the senior and you only get called when there's a problem/case, your time may free up as well.
Not saying it's impossible, but as smq123 alluded to above there will be plenty of times where if you want to get 1.5hr in the gym then you're probably giving up your other free time activities (dating/family/other hobbies/sleep). Not to mention studying/prep time.
If you're the type of person who exercises that much regularly, maybe keeping a consistent exercise routine actually energizes you. For me, doing a 1.5hr workout (lol whenever that happens) saps my energy and def makes the rest of the day harder. Only got so much energy (and time). An hour of netflix at the end of the day is way more doable than fitting in an hour of exercise before or after work.