Foam rollers are used for self myofascial release. Myofascial release is a technique in which muscle tissue is stretched and manipulated to relieve tension in the fascia, the thin tissue covering the muscle fibers. It works by breaking up fascial adhesions and also by manipulating certain neuromuscular receptors to allow muscles to release any tightness. A foam roller allows you to use this technique on yourself. This video shows how to use the foam roller to target specific areas.
4x10 PVC Pipe - $15
Yoga Mat - free to me
PVC Cement - free to me
Gather your materials and find a well ventilated space. The PVC pipe is available at any Lowe's or Home Depot. I got the whole long piece of it, but you can get a pre-cut piece. I used an extra yoga mat I had lying around and PVC cement the my contractor had leftover.
Cut your PVC pipe into the lengths you'd like your foam rollers to be. I did one of about 24" and three of around 13". If you don't happen to have a contractor at your house with a large table saw already in use like I did, wrap the pipe with electrical tape at the cutting point and use the hacksaw to cut through the pipe.
Measure the length of yoga mat you'll need to completely cover the outside of the PVC pipe. Leave about a half inch on either side. Sure you can use a tape measure and be precise about it or you can use my method; put the pipe on the mat and cut.
Make sure your pipe is laid out straight on the mat, swipe PVC cement onto your PVC pipe or yoga mat in about 1.5" lengths. After some experimentation, I found putting the cement onto the mat to be the most effective method. Don't skimp on the cement.
Apply pressure on the cemented section. Allow the first section to dry for about 5 minutes.
I clipped the ends of the first and last sections I cemented to make sure the edges stuck and I rubber banded the middle to make sure it didn't buckle and to make sure there was a nice smooth edge.
Continue working your way around the pipe in 1.5" sections, making sure to get cement to the edges of the pipe and to the last dried section. It dries pretty quickly so you'll only need to give those sections a few minutes to dry. Make sure to press down on these sections while they're drying.