Any updates on new programs? It'd be great to see anything new; it's been quite a while since there's been any additions to the site.
I'd love to see Justin do another round of True Beginners, pushing us all a little harder. Come on, Daily Burn, get it together and put some new programs out there.
Your joints are filled with a lubricating liquid called synovial fluid. (This is what Justin is referring to when he says something about lubricating your joints) There are bubbles in this fluid and often these bubbles will pop and make it a sound. It the same biophysics you hear when you crack your knuckles. As we get older, the fluid becomes thicker and less plentiful, so there tend to be more bubbles popping as you warm up the joint.