Change my routine? Never!!
I know that we all hear that it is important to change up your workout routine, but I really think that very few people do, basically because we are trying to fit our workouts into a very hectic lifestyle. Why is it important to switch things up? Mostly to stave off boredom: you are much more likely to do something that you are totally stoked about and really makes you excited and energized. But, we also forget that once you get into shape, unfortunately, you ned to work really hard to stay in shape or to sculpt your body, and if you do the same thing, your body will plateau (I know the dreaded plateau!)
I tend to run a lot (obviously), to change it up I do interval training: sprints that total a couple of miles, lunges, high knees, and in between I do push-up, crunches (about 8 different types), and I NEVER stop to take a break. It is sooooo much harder than my runs, even though I sometimes dread those days, interval training days always seem easier to me mentally, but then doing it is a true test of my physical abilities! I also have been trying to swim (I am horrible at it...like to crappy to go to a gym) in the ocean and it, again, is such a change for my body and I know that I am burning so many more calories because I am STARVING afterwards, which makes it all feel worth it!!
Also, as of late, I have been adding pull-ups to my routine as well. Now, for everyone that was tortured by the "Presidential challenge" as a child (like me) and who has nightmares of the pull-up....you need to get over it and give them a try again. They are an amazing full body workout and really challenging- another true test of your physical abilities. I can only do 8 in a row, and that seems like a ton, so even if you can do one or 2- go on with your bad self and feel good!!
Try to avoid the plateau and overworking of the same muscles, and I totally promise that you will see a difference in the sculpt and tone of your body. Also, you can make those high intensity days more frequent, then add in another type of workout one day a week (very low intensity like yoga) to give yourself a mental challenge and keep it fun, and shape your body in new ways!
Yours in Good Health!