This is coming from an anorexic XC runner.Lay off calories, stick to no more than 2k a day. Pushups, planks, crunches, side planks, t pushups, jacknives, and resistance training. Also, 4 sprints all the way around the track boosts your metabolism. So if you do that before walking or running, you'll lose fat faster. Also, you are a great build for hill running. Hills are great and make you stronger/burn fat.
Also, grilled chicken is great. Apples, watermelons, lemons, or other watery fuits=more food less calories. And salads with light mustard dressing or vinagerrettes very healthy. Oh and lots of carbs with some protein and little fat.
I don't agree at all with you saying that he has to bench heavy and squat heavy. Depending on how he's built, he can add a quick few pounds onto his body just by doing light weighted exercises. I am not a huge fan of benching heavy bc I play baseball and I'm a pitcher so I might be slightly biased on that point. I love squats and everything that they do for your body. Not only does it work your legs, it works your butt, abs, and back. Personally, I don't use a belt when I squat so that I can work on those other stabilizing muscles through my body. All personal preference imo whatever you feel safe about doing. Go down slowly with a proud chest and explode up through the hips. Another easy way to gain a few quick pounds is to hydrate yourself better (water). Your body will hold liquid weight as long as you are well hydrated. I aim for about a gallon a day depending on what I have planned for that week as far as athletics go.
Sticking to less than 2k calories a day is a bad piece of information, especially when you don't know the metabolic demands of op
I feel, it can be effective but it's usually just training with extreme unrealistic expectations of the human body
Problem with CF is that it's ran by an idiot, and it's too easy to become a coach. There are gyms ran by intelligent, educated trainers, and great results can be found there.