Fair. Still some mistakes here and there though. (Pecs too long, pelvis too wide, overall body shape being too tubular....likely the shoulders need to be broader too.)
Try redrawing the person in skin; it'll be far easier to spot the mistakes which you normally don't find here. If you haven't already studied proportions, I suggest you do so now as well. Sycra's videos should teach them.
Keep in mind that knowing the muscles isn't as important as being able to capture the human form. (In that regard, I'm less well versed in what muscles there are and where they go, and more focused on HOW the body looks, if that makes sense.)
Do a few more of these in different poses and angles, be sure to add the version with skin. When you are confident, you might want to go forward with gesture drawing. Posemaniacs has a couple of poses with skinless models, but I also suggest
http://artists.pixelovely.com/practice-tools/figure-drawing/ which has many more models and poses to choose from. If you (and anyone else with you) aren't squicked by dangly bits the nude setting is best.
