Simple question for my more knowledgable amigos on here... I'm going to do the London marathon in 10 weeks... I've put on about 20 lbs of muscle in recent times and I don't want to lean out. Can I use the same principle of one big strength session a week to retain mass or will I lose a lot of size? Any tips to retain size- also any marathon tips like pace etc.. I've done a 10k in 38 mins with no training I can run really well but this is a different level.
I've never trained for a marathon but one of the guys I once ran with has done so many times. We would run 5 miles a couple days a week, 6-8 miles one day a week, 10 miles one day and and on Saturday or Sunday he'd run 15 miles for his long training day. He'd take 1 day off after the long run and another whenever he felt he needed a break for a second day a week off. I only ran 4 days a week and totaled 27-30 or so miles a week. I was lean to begin with and never gained any weight when running, but I never lost any either. When we first began running, he had been doing so for about 6 months and had lost about 30 lbs. and was still heavier than me. That was the main reason he began running------to lose weight. I helped him pick up his pace over the next few months and our distances increased from 3 mile runs to the following. We would run together at a 6 minute a mile pace up to the 10 mile distance. When he ran the 15 mile distance, he'd cut the pace back to roughly 7 minutes a mile. As far as I can remember, his personal best for the marathon distance was 3 hr.s 40 something minutes and just under, or right at 8 minutes a mile. I believe it comes down to how hard you train and what time you are trying to achieve. Fact is, the body type for long distance runners is quite lean, almost looking like anorexia. I watched the Kenyan's and Ethiopian's cross the finish line at the Crescent City Classic 10K and those guys are built like match stick figures.
I used to be a fairly decent marathoner until about 2000. I saw lots of very good distance runners with considerable lean mass, in fact a few of the army lads destroyed me in a half marathon and made me see sense about being a weak, ill, over-trained endurance junkie.
You could keep the same muscle size but the composition of the fibres would change from the training required for a marathon, you'd probably lose a bit of strength and power p4p. You just have to make sure you take in enough calories. When you train in a certain way you also train your body to send more blood to that part of your body being used, so your proportions may change a bit.
Should be able to keep most of your muscle size. Resistance training volume can be reduced while still maintaining. I'd increase protein a bit (nothing excessive) and obviously keep calories high.