I like the "I don't have time" excuse. I have used it many times myself. An instructor gave us an assignment to keep a 48-hour log of how we spend our time. It was a chart with 15-minute increments. It was amazing to see on paper how much time I wasted each day on Facebook, AllNurses, just being lazy on the couch, etc. Something as simple as taking a 15-minute walk each day will benefit you greatly. Take the kids with you, kids need fresh air and exercise too! Everyone has at least 15 mins a day. I think most of us just don't FEEL like working out. It can be hard to find the motivation to get up and work out after a long day of class/clinicals. So this semester I plan to get up early before class and do at least 20 mins of cardio at the gym at least 3x per week. The gym is 1/2 mile from my house, and my husband is working the early shift so he can wake me up early so I am forced to go
Also, I have two big, young dogs that need daily walks. They give me sad puppy dog eyes until I get off my butt and walk them. Find a classmate or friend who will keep you accountable for working out. If there isn't a gym close by or you can't afford it, walk/jog outside, or, spending $20 at Walmart will get you a workout DVD and some weights. Try Jillian Michael's 30-Day Shred. It is a killer! I find that I have a ton more energy, better focus, and I sleep better when I do 15-20 mins of moderate exercise daily. You need all of those things to be successful in school.