None.
Journals occasionally have good studies, but generally they have mostly worthless stuff along the lines of what Shaf is talking about.
The only thing I might recommend is Alan Aragon's research review:
http://www.alanaragon.com/researchreview
But yeah...
It's better to learn stuff from coaches who put out articles. For example, look around the web for stuff people like Dan John, Eric Cressey, Mike Robertson, Bret Contreras, etc. people put out because they contain useful information about training, especially with athletes or injuries in a lot of cases.
T-nation actually has had a good rash of articles in the past few months. Just check out some of the authors sites and they should have lists of articles they've written that are very good.