These workouts can be done at home or even in your office. With this workout plan, you can work out for just a couple minutes at a time, several times throughout each day, 5 days/week.
This consists of only bodyweight exercises done for about 2-3 minutes, 6-8 times per day, throughout each day. Now obviously if you work a normal office job, you are going to have to not be shy about doing a few exercises in your office and having your cube-mates watch you. Actually, even some people that have tried this have actually gotten their co-workers to join them.
If you work from home, or are a stay at home mom, there's no reason you can't fit these in throughout the day while at home. If you end up having a busy day with meetings and so forth, and can only fit a couple of these 2-minute workouts in, then so be it, but try to get as many done each day as you can. If you're on a normal 9-5 office schedule, I recommend doing your 2-minute workouts every hour, on the hour, with the exception of lunch. Try doing these at 9am, 10am, 11am, 1pm, 2pm, 3pm, and 4pm.
Some of the bodyweight exercises that are the best to focus on are:
* bodyweight squats (and variations) * pushups (and variations) * forward, reverse, or walking lunges * up & down a staircase if one is available * floor planks (holding the plank position from forearms and feet) * floor abs exercises such as lying leg thrusts, ab bicycles, etc. * one-legged bodyweight Romanian deadlifts
This list is not fully comprehensive, but I wanted to keep it relatively simple. If you know other good bodyweight exercises, you can add those to your routine also. If you want to keep it real simple and don't want to get down on the floor for anything, you can stick to squats, lunges, and pushups and still get great results.