Do you think that there is truth to the whole "21 days to create a new habit" thing? I'm not sure if there's any truth to it, myself, but I do believe that you have to keep going. Our minds are so adaptable that just the tiniest spark can ignite a flame. You want to run a marathon? Make it a habit to run and eat healthy. It has to become YOU. Be known as the "healthy girl" at work. The girl (or guy) that talks about exercise and eats fruits and veggies for lunch. You never know who will be motivated by YOUR habit.
I love this plan from Carissa @ Fit2Flex. It's no secret that a strong core can improve your running. This schedule is something anyone, no matter how busy, can fit into your daily routine. Don't know how to do the exercises? Google it! That's what I do!
Now get down on the ground and hold your plank as long as you can!
Have a great and healthy week!