Obstacles will always come in life but its how you respond. Take action be active and live healthy, especially when others depend on your livelihood.
Planks are the safest way to get sore abdominals but not a sore back. In fact a sore back from planks is a indication that your abdominals have fatigued. At this point either hold the plank longer or pause then do more. This video includes various plank positions used for every level of fitness, its in progression order so start from the beginning and try til the end. If you cant make it all the way. Keep trying do at least 10 repetitions per exercise, advance do 20 repetitions.
Sometimes its hard to get motivated to work out. When your fortunate it enough to have people around you, you have a choice. Chill or be productive, Ive always been a active child as we get older it gets harder. Live young and grasp knowledge of wisdom and time. Don't waste time use it wisely and this is how we use time at IMFITNESS.TV
I put together a cool tutorial pull-up workout for beginners - experts. Core work as well.
Go to link: http://youtu.be/nYJwuzQfloE