Medical checkup

I got the results of my recent medical checkup today. Basically I'm healthy, so that's good. However, my LDL (bad cholesterol) is borderline, which is not good, though I have very low levels of triglycerides.

Bad cholesterol? We all know what that is, and definitely that's not a good path to go down, so I gotta start working out more, especially when those new skates come! ;) But what in the world are triglycerides? I searched Wikipedia and all, but still I don't really know what they are. I know its got something to do with fat (so I'm really not that fat after all huh?) and something to do with arterial blockage, so it's probably a good thing that I don't have much of this stuff. But I also see some websites say that its not that much of a big deal compared to LDL (damn). So looks like I still need to work out more after all! (not to mention that IPPT is just around the corner....)