I've seen these terms a couple times here already. Also, is there a good place to ask these questions? I feel "what are some good exercise terms and their meanings" would get closed.
Box Jumping is one type of Plyometrics exercise that is based off high impact jumping routines. Plank is a type of AB workout that focus on holding a position with your back skyward, elbows on the floor supporting the body while keeping your back straight maintaining a straight line from your shoulders, to the hips, to the knee while tip toeing. While you are at the Plank make sure to keep breathing. In fact, keep a consistant breathing pattern while doing any exercise. Keep your stomach, butt, and leg muscles tight during the exercise.
Planks are an excellent way to build up your "six-pack", as well as numerous other muscle groups. Follow the link to see an image of what it looks like. It's ridiculously easy to do, and can be done anywhere, at any time. I do it both as part of my workout routine and as a short pick-me-up while in the office.
Two points to remember about the plank:
- Keep your back and legs straight. Continually check yourself to make sure you haven't sagged.
- Keep breathing normally. Don't hold your breath.
Once you have it down, try holding the position for longer and longer. There are also many variants that you can find by searching online; ways to make it easier (rest on knees), ways to make it harder (put toes on a balance ball or against the wall), and other stuff as well.