I have no idea if this guy is clean, butnige seen nothing on his thread that makes me think otherwise.
Yes, he's a muscular guy, but he only weighs ten pounds more than me and some significant portion of that is in his legs, which can add value in the marathon.
Yes, he's extraordinarily lean, but probably only a couple of body fat percentage points leaner than most other good marathoners.
Yes, he ran fast, but it wasn't an outlandish time, being just under a 90% age graded performance per a previous poster. You'll see those in just about every world major marathon and quite a few regular posters on this site do that annually at one distance or another.
Yes, he came back very quickly from an injury. So did I about a year ago, going from running one mile at 8:30 pace at the end of September 2016 to being very competitive by early March and finishing top 3 in my age group at Boston in April.
No, they do not typically test age group winners at these races, at least not in the US. The logistics are nearly impossible as they have no idea who is an age group finisher until hours after the athletes have cleared the finishing chutes.
The guy obviously has some good genes. No, that doesn't mean he isn't doping, but why would we automatically assume he is? Because of him being unusually cut to the tune of 2-3 percentage points and carrying about 5-10 pounds more muscle than you might expect?