Is Weight All The Same? Dumbbells vs Ultimate Sandbag Study By Josh Henkin
It might be the MOST annoying saying in all of fitness. I have even heard some of the smartest and most accomplished strength coaches fall prey to it:
"Weight is just weight, the body doesn’t know the difference."
At first glance, it makes a lot of sense! It reminds me of an old joke, "What weighs more, 1000 pounds of feathers or 1000 pounds of rocks?" Does science and the real world tell us anything otherwise?

I can remember my first time flipping tires, lifting atlas stones, and lifting strongman logs—holy cow! I had lifted barbells for ten years and had some good lifts, but all this stuff was totally humbling. I was strong, and thought that just couldn’t be right! But, the truth is we all have had a similar experience when trying…read complete article: http://www.dragondoor.com/is_weight_all_the_same