To paraphrase Jamie K. Schmidt from her fabulous workshop on Writing Novellas, there are 24 hours in a day. That breaks down into:
8 hours of sleep
8 hours of work
8 hours for everything else
8 hours for everything else?
That’s huge! That’s 56 hours a week! That’s more than enough time to fit in everything, including writing and exercise (and laundry, grocery shopping, cooking, cleaning, and most importantly, nurturing the important relationships in your life).