I've been training now for about 8 months and have lost quite a bit of weight, dropping from about 200lbs to 165lbs and at the same time making significant gains in muscle mass. My body fat ratio has gone from around 25% to aroubd 15% (measured with a manual body caliper so I'm not sure how accurate that is) and my endurance/stamina levels have improved vastly (I'm doing a 10k run in a couple of weeks and my best time to date is 43 minutes. Aiming to get in for around 40/41 on the day).

My problem is my backside. I can't seem to shift the fat from there no matter what I do. I now have ok definition on my upper body now and can almost see my 6 pack for the first time in my life but the fat on my buttocks refuses to go. Do you think this is a genetics thing and I'm just destined to go around with a fat bum for the rest of my life? I mean, it's not excessive and I've lost some weight around the area, but it just seems a bit out of proportion to rest of me.

Any ideas/training tips/etc?