Hello!! I'm new to this forum and I need some quick answers about lifting please! I have been into distance running for a few years and recently wanted to add weight training to my routine to gain strength and perhaps a little muscle definition. All the running coaches I talk to preach this "high reps low weight" business. They say lifting heavy will ruin endurance and make you bulk up. After 6 months of this high rep routine(20 reps) I didn't feel like I was gaining anything. I only could increase weight by very little over the 6 month period. I went ahead and tried a 12 rep routine with a weight that tired me by the 12'th rep. Within 6 weeks I noticed I was gaining muscle mass and I put on 5 lbs. I was also making improvments in strength as I was progressing much faster than the former. I held the same eating habits which is a typical runners diet of high carbs, protiens, fats etc.. I run 7 days a week and most days cycle or elliptical along with it so I do huge amounts of aerobic exercise with only 2 days of weight training(full body each day).

Anyways, my goal is to gain STRENGTH but not all that much muscle mass and no fat at all. I'm just looking for a more healthy looking physique. Today I stand at 5'7" 122 lbs male(thats with the 5 lb gain) and just look kinda thin and dorky. I'm aiming for muscle definition without all that bulk and I don't want it to negatively effect my running times. I'm currrently is a base buidling phase of my running so I must limit the amount of anaerobic activity. Is their a possible weight training method out their that will help me achieve this? Is this 20 rep business the only way for me to go?

Thanks in advance, I appreciate anyone who takes the time to help.