Push ups! Simple. Good workout for arms and core muscles. Do 10-20 when you first get up. That's less than a minute.
At work, instead of sitting, would you be able to do your job standing up? One of my sons works at a place where they're into keeping employees fit (to keep their insurance rates low) and they got him a desk where he can stand or sit to work at his computer. He stands part of the day now. There are risks to both standing all day and sitting all day, but experts seem to agree that doing some of both is better than all of one. If you can't stand at work, at least take small walks during breaks and lunch.
Check the portion sizes of what you're eating (just google portion size). Many people don't know what a one-serving portion looks like. Portion size has crept up over the years. In the 1950s and 1960s, an adult-sized soda was 7 ounces!
Age 61, Height 5'9"
March 2010 145 lbs, Jan 2013 173 lbs
1st Goal 145 lbs 5/25
New goal 140