Compression garments for athletes, and other uses, aren't new news.
They work, and that's been widely know in sports science, for years.http://sportstrainingblog.com/sport-general/compression-garments-athleteshttp://www.jssm.org/vol5/n1/12/v5n1-12pdf.pdf
Many studies have shown increased performance. Some says it's "muscle flattening", which helps the muscle work better. Some studies say "nuts." Depends which study you want to go with.
You'll want to google on this to explore it further, if you really want to know.
Most serious science says that you'll benefit most from wearing the compression garment AFTER exercise to help with recovery.