Help!Losing the last 10lbs..what to change in workouts.

Hello all!. I am not new to MFP, but I am new to the forums, so hello!

To give a brief run down, I have lost about 50lbs over the past year, and about 27lbs since I started using MFP. I went from a size 14 to a size 6 in jeans, started at about 200lbs and now fluctuate between 148-152 lbs on any given week for the past 3.5 months. I went from 30% body fat to 20% body fat. I was never very concerned about the physical weight, but more about my clothing size, BFP, and overall fitness level. I have accomplished a lot, but I would like to reach my goal of 140lbs and/or 18% body fat.

I currently run about 30 miles a week and regularly compete in road races, especially 1/2 marathons. I am also training for a Spartan Race in July, which is a mud/obstacle course race. I love running, but really do not do as much strength training as I feel I should. If I have to the choice of how to spend my workout time, I would much rather go out for a nice run as opposed to doing push ups, pull ups, squats, or weight training.

I understand a large problem of this portion of weight loss is that once your body starts to get towards your "ideal" body weight, it becomes harder to loose weight. I have run into a couple of problems with MFP in this regard. I have recently switched from a highly active job that required a fair amount of physical labor to a desk job. Subsequently, I switched my activity level in MFP from very active to lightly active, since my only physical activity was going to come from my workouts 5-6 days a week. My daily calorie allotment to lose 1 lb per week dropped from 1760 calories a day to 1500. Since then, I have kept consistent with my logging, met my calorie and expenditure goals, and have not lost any more weight over the past 4 months and have not made a dent in my BFP.

I have maintained a very good high protein diet. I don't eat junk food, drink sodas, or eat sweets. I eat tons of veggies and moderate carbs (enough to keep my energy up and to help in my runs). I also do not eat a ton of fat (less than 35g a day. If I do eat fat, it is healthy natural fat. I eat mostly organic, all natural foods. Nothing overly complex with lots of additives. Big focus here has been CLEAN fuel to burn.

My question (I apologize for being long-winded here) is whether I need to change my dietary goals (eat more) and/or change my fitness plan to incorporate more strength training to raise my metabolic rate. Given that my workout time has become more limited because of the job change, I want to make the most of the time I spend working out. Running is very important to me, as I am working on cutting my 1/2 marathon time from 2:13:26 to 2:05:00, so I need to train in that regard. But will more strength training help in cutting the BFP? I want to be able to see the abs that are under an inch 1/2 of fat and the muscle tone I have gained. :-) I feel I am so close, but have hit a bit of a wall here.....


PLEASE HELP!

Thanks!