Finally decided to give these a try after believing that foam rolling is all I needed. After a 40-mile bike, I headed out for my 10k run and became a believer straight away. These compression sleeves are outstanding! They really do keep the calves from tightening up. Like a constant massage, the sleeves keep the calves happy and in continual contraction-relaxation. For $30 at swimoutlet.com, it's a no-brainer.