I chose to try out the KOALA Bands because they are not bulky and they are also black and white which match pretty much everything I wear at the gym (yes, that matters to me, lol). First time I tried them, I fell in love with the pump that they gave me. Not only was the pump amazing but they were actually comfortable to wear, not bulky at all. I had a major arm pump my first arm day, and was surprised that I didn't even have to lift as much as I normally do to get the same effect, if not a BETTER effect while lifting. It was intense! Then when I tried them on my leg day, it was AWESOME. The pump was INSANE! I only had time for a quick 30 minute workout, but by the time I was done, my legs were massive and the intensity of the workout was major. I included a picture to show how incredible it was! I'm now recommending these to ALL of my clients who are seeking hypertrophy and will be including these as a necessity for ladies who take my glute classes.