I'm in the army and my push ups and sit ups are easy to max out but keeping my 2 mile run under 13 minutes requires that I stay on top of my cardio just as much as I lift. I don't have much of any kind of diet right now aside from not eating alot of fast food, soda, or candy snacks. My gym routine is pretty simple I do two muscle groups a day 4-5 days a week. To condition myself to a shitty army where I have to keep going environment I do push ups, sit ups, or something in between every set then continue my next set. I feel like im getting bigger and stronger but ever since I've become dedicated to hitting the gym ive lost alot of weight. I was bouncing around 160lbs for the majority of the last 10 months and now im at 145. How can I gain this back but as leaner muscle mass without losing my run time and stamina? I'm assuming fighters do it all the time, but how?