This design that won an honorable mention at the "Re-Invent Design Competition" organized by Procter & Gamble and Design Boom, seems in fact like a very neat idea for the product.
Is not that I like cleaning or exercising for that matter, but I believe this bottle has pretty good chances of being recycled as dumb-bells (filled with water or sand) and will be reinforcing the whole positioning of the brand: strength.
Personally I find it better than the actual winner.
I mean, I rarely buy cleaning products and I would buy these! (Disclaimer: is not that my house does not get clean, is that the girls that help with that they come with all the products they need...)
Link, via Young Designers Italy