We all know that gravity is a breast's worst enemy, but strapping weights on top of them can only compound the gravity problem. It is definitely a bad idea if you want to keep 'em at all perky. As you can see in the video the weights on this vest are located in the "pectoral-area," which is fine for men, but for a woman with any amount of boobage it quickly becomes uncomfortable. I am only a B-cup but after wearing this vest for a few minutes the girls felt very squished and deflated. I don't know what the longterm effects of using this vest might be, but I'm not interested in finding out!
About ten years ago I had a chance to demo a weight vest designed by a woman for women, The Walkvest, which loads the weights around the waist and then tightens them down with a strap so there was no noticeable compression on my breasts. A Weight Belt is another option that might be better for women.
I gave this product four stars because it seems really well-made and easy-to-use, but it should be marketed as a men's product. Perhaps the company could produce a similar vest for women that moves the weights down to waist level allowing women to enjoy the obvious benefits without damaging delicate breast tissue.
I always find it helpful when I can watch a video review showing a product in use - it oftentimes helps me to understand the product better than I can from the manufacturer's written description. I've been inspired by the great video reviews I've seen on Amazon, so I hope my video review helps you in a similar way.
PS - It always makes my day to know that people find these reviews helpful. If you'd also like to ask a question or leave a comment I usually respond the same day, so if you have a question or comment (even if it's just to say, Hi!") feel free to post it below.