Yesterday a friend of mine asked me if it would be better for her to go to the gym for only 30 minutes after work or not at all. Wholeheartedly I said, "30 minutes!" It sort of made me chuckle, but then I thought, she must not be the only one thinking she has to do it all or it's not worth it.
The all or none approach does not apply since anything is better than nothing when it comes to fitness. Not only is doing something active on most days good for our fitness but it's also good for our minds. To me, it's a lot easier to keep up with a constant routine (even if the duration varies) than starting back from square one. So even if you're just doing something for 20 minutes, that is still something and it will make working out for 30 minutes the next day, and 40 minutes the next day, seem like a much easier task. So lose the all or nothing approach because when it comes to your health, anything is something.