[speeder]

All of these videos are worthwhile but the first one, (back/core workout), is invaluable. I had disc surgery 15 years ago, when I was 42, and doing back exercises is my only insurance against another injury and/or a life in pain or worse.

Hardly anyone really works their core hard and regularly, it requires very specific exercises. But the guy is right about the value of it in avoiding back problems and it's a physiological fact that you cannot have a strong gut and weak extremities. The inverse is absolutely possible and seen all the time.

If you have an extremely strong gut and lower back, you will stand and sit straight and be slim, no matter what your age. I'm talking men or women and 80 years old. But almost no one does the required exercises.