For me what is necessary is my daily workout. It seems to give me a sense of calm, and focus, something I lacked when I wasn't working out. I have to say it showed in my work.
I have been working out religiously now for 3 weeks and it feels good to get back in the swing of a regular workout, I find I have more energy to look for a job, and maintain my diet. Without exercise I think I would have already failed at trying to lose weight again.
So here is my beginner's routine. Now I should note that I had some level of fitness despite my obesity because I did workout sporadically and make an effort to walk everywhere I possibly can.
Monday - 30-45 minutes of walking, and lower body strength training.
Tuesday - 30 - 45 minutes of Swimming laps, 5 minutes of Abs(from my Ab Workout App)
Wednesday -20-30 minutes of Elliptical, and Upper body strength training
Thursday -30-45 minutes of Swimming laps, 5 minutes of Abs
Friday - 20-30 of elliptical and Core strength training
Saturday - 20-30 minutes of a leisurely swimming or water exercise
Sunday - 30 - 60 minutes Leisurely walk around town - window shopping - or in a local park
If you notice Saturday and Sunday aren't hard core exercise just something to get my body moving in the AM. Monday, Wednesday and Friday are my strength training days and Tuesday/Thursday offers some hardcore swimming which gives my knees a rest, but also burns major calories. Swimming 1 mile is like running 4 miles.
This may seem like a lot, but if all I can do it 10 minutes I would do that and call it a day, just as long as I get something in. Fortunately I get to burn extra calories while I am unemployed. Of course it is important to change your routine so your body doesn't adjust. So at the end of 4 weeks this routine will change. I am thinking I might like to add in some Zumba.