Is working out 7 hours a week suitable?

Unfortunately I can't space it out as an hour a day because of my work schedule. But it's 3 hours on Sunday and one hour on Monday, Tuesday, Wednesday, and Saturday.

It's mostly strength training to build muscle because I'm underweight and need to put on 5-10 pounds (doctor's orders). Monday, Wednesday, and Saturday have about 45 minutes of cardio each.

I work out with trainers and instructors, not on my own. I don't trust myself to do it right.
Is working out 7 hours a week suitable?
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