Rediscovering "The Plank" for quick afternoon energy

I recently got back into full-time work after about half a year on an adjunct's schedule that allowed me plenty of time during daylight ours to take part in my favorite strenuous form of exercise - hiking. But now that I'm office-bound five days a week, I've been struggling to find time for getting a regular workout. I do medicine ball exercises in the evening before going to bed, but I like to get staggered workouts throughout the day. Thank goodness for The Plank!

This exercise is easy to do, and for instructions just follow this link, with instructions from ACE, the American Council on Exercise. I just did several sets of the front plank followed by a couple side planks, and my mid-section, especially lower abs, and rear-thigh muscles are burning. I'm flooded with elusive mid-afternoon energy, and I'm ready to take on my next client!