Arguably the best underwear I've worn. They feel like compression shorts around the thigh/butt area (which is why I said they fit a bit small, if you're a bigger/more built guy, you'll probably want to go up a size or two) and are loose in the front. The drawstring allows you to adjust everything to your personal liking. For the busy active days, I tighten things up and keep going and on more calm days, you can loosen things up. I really like them and will get a few more pairs.

For reference, I'm about 205lbs in good shape and I bought the 36-38L. They fit very snug and I had to get them to work for me. I will get a pair of the XL and see if those work better.