Too much muscle?

Even if you are very lean, thermoreglution is likely the biggest limiting factor in the marathon at this weight. This is why many marathon runners are short and skinny. However, in cold/cool conditions, taller and heavier individuals often do better. Just look at Boston marathon 2018 with that torrential rain, 20 mile headwind and 40°F temperatures. Many runners with a traditional "marathoner body type" ended up getting their butts kicked! You should definitely go for an OTC in cool weather.

As for weight training, it's great for injury prevention as well as enhancing strength to weight ratio, another important component to running performance. You would only gain weight in a caloric surplus, not by lifting weights in of itself.

If you would give up muscle to be a good scrawny distance runner then you have too little brains.

I'm built very similarly. 5'11 and 160 with big legs that I maintain even if I never lift. I've tried to skip weight lifting to shed weight but ended up with an injury but tried intermittent fasting and watching calories as well and became super tired on runs. I think there is a balance of weight training lower body so as to have less weight in the upper body and injury prevention and thus a higher VO2 max without watching calories too much but eating healthy. With enough mileage and training for a marathon it should balance itself out eventually

no, your body will naturally settle into its equilibrium state. dont stress. unless youre lifting to the point that you feel its affecting your recovery, its not a big deal.

What kind of rep ranges do you hit in the weight room? It's possible that since you're using a light weight, 30is lbs, that you do a lot of reps. If you're doing lots of reps, you're going to get more hypertrophy. If you do, say, less reps, but more weight, you'll pack on few pounds and develop a little more power. There's a lot more to it than that, but something you might want to consider/read up on.

fewer* not few

I am a man and have a similar build. 5'10" and at my absolute lightest I can't get below 160 without making friends and family alarmed. I naturally have a lot of lower and upper body muscle. When I finally just embraced this and stayed strong, I settled into about 165 (with very little weight lifting) as my best racing weight and literally never got injured. Being strong is a gift that most distance runners don't appreciate. It really decreases injury and allows you to gain raw speed easily.

When someone is 5'10" - 5'11 weighing a "muscular" (LOL) 160 and worry about how "big" they are, this is body dysmorphia territory.

This exemplifies how this damn sport has a serious, serious body image/eating disorder problem.

Just to clarify, when I got down to 160, I was so lean that my gaunt face, veins, etc were not my own body image issue, but (as mentioned) alarming to people I know. Now that I run less and lift weights just a little, I quickly settled into a "healthy" lean 175 pounds. Dunno, but I'd guess I'm around 12% body fat. A little abdominal definition.
I never had body image or eating issues.

He was talking about the OP.

Ashton Eaton is 180 pounds of pure muscle and runs like a 410 1500m during a decathlon on less than 10mpw

You're probably running 10x his mileage, if you can't reach your marathon goals, the weight isn't your problem.

I agree with this post. I'm a male, 6ft and 145lbs and usually think how can I get thinner. Skinny fat, no abs, but all in the name of performance.

I'm 6ft and 160lbs trying to get down to low 150s again. I lift 2x per week sometimes 3 and have some ab definition and decent biceps/shoulders/back etc but not enough. Need to do more sprints and hills to get the gains,.

lmao dont lie to yourself you don't have a lot of muscle if you're using 30 lb dumbells

This poster has good advice but the claim in bold although mostly true for most people is not correct, especially for weight trainers. You can gain weight in a modest calorie deficit while weight training and you can lose weight in a modest calorie surplus (less likely but possible under muscle loss), the reason being that fat and muscle have different densities, different amounts of energy needed to be created, and different amounts of energy produced by burning them.

The commonly cited “it’s just physics” justification is incorrect as the relevant physics here dictates conservation of energy and conservation of mass, neither of which are violated during body recomposition that can result in the above counterintuitive scenarios.

Or perhaps the reason OP says he’s is naturally muscular is because he is so despite using just 30lb dumbbells for compounds.

This is 100% BS. You need to explain how someone can gain any weight/body mass when it is consuming itself (fat stores, muscle) because it's not receiving enough calories (caloric deficit)?

Sure, happy to explain (along with a gratuitous note that it’s a good idea to triple check your ken of knowledge before rushing to call something BS). Couple references for claims are below, both well known for digesting scientific articles to make them easily palatable to the general public. All numbers below are approximate estimates, but scientists have no disagreement on the qualitative conclusions based on these estimates.

Calories from burning a pound of fat: ~3600

Calorie surplus needed to store a pound of fat: ~3600

Calories from burning a pound of muscle: ~700

Calorie surplus needed to generate a pound of muscle: ~2700

Density of fat: ~0.9 compared to water

Density of muscle: ~1.1 compared to water

Consider a person who has gained say 1.2 lbs of muscle (using 2700x1.2 = 3240 C) and lost 1 pound of fat. They have done so, i.e., gained 0.2 lbs, at a calorie deficit of 3600 - 3240 = 360 C.

It’s likewise easy to show that one can either gain or lose weight at maintenance as well as show that one can lose weight in a surplus. The differential densities can be used to show that one can become smaller in size while gaining weight or bigger in size while losing weight; or to show that one can maintain weight in an overall modest surplus or deficit.

[1]

mennohenselmans.com

Can you gain muscle and lose fat at the same time?

Menno Henselmans

We live in sad times for bodybuilding. Although broscience is finally losing face, it's being replaced by what I can only describe as bodybuilding nihilism ('nothing-ism'). Nothing supposedly matters. Nutrient timing? Just ea...

Link:mennohenselmans.com/gain-muscle-and-lo...

[2] Can You Build Muscle In a Calorie Deficit / Lose Fat In a Surplus? (Science ...YouTube · Jeff NippardNov 17, 2018

I don’t have a body dystrophia issue. I have always been lean and muscular and certainly do not think I am “big.”

I am a former D1 swimmer and was successful enough to be able to compete in the trials in swimming. Now that I’ve taken up running, I thought it would be a fun to chase a big goal and get to experience the same thing in running. I was genuinely asking for advice for somebody like me that is naturally muscular when it comes to running a marathon in terms of what types (if any) of strength training others might do.