I am not claiming to be an expert in this but I don't think that is basically right. Resistance training - eg weights- leads to hypertrophy -i.e. a large increase in the number of myofilaments - and this is what increases the visible size and shape of muscles. The basic reason is that they are being asked to do more of one particular type of work (the resistance in that particular direction) and so repetitions lead the body to do that, so the muscle can be stronger, so it can do the work more efficiently.

However for long distance running what the muscle needs is endurance rather than strength. I am of course certain that Mo Farah's muscles are far stronger than the majority of the population, and certainly plenty strong enough to propel him forward at his pace, but they don't need to be any bigger, and if they were, they'd weigh more, so he would suffer a weight-related handicap. (Possibly his glutes excepted as they provide most of the driving force). They need to be strong enough to absorb the repeated landing and bounce off the running surface for the next stride.


I have no link for this, but I'm pretty sure that long distance runners usual routine in the "off season" does include much more strength work to increase strength and muscle size/mass, but they then aim to reduce that mass/weight of muscle by the start of the season back to their fighting weight.

Well, it depends on your aims. It's funny, we've got a lot of people in my part of our company into running. They start out running for weight loss. Then get the idea of marathons and racing, which changes or should change, the approach entirely - now needing to eat to fuel running and structure training around targets and progression. A few, having realised their miles a week sees them eating less and carrying more fat than me are coming around to the idea of resistance training though.

Gov guidelines for protein are just 45g a day. That seems far too low....any exercise at all I'd think 1g per kilo bodyweight, and 2g per kilo if weight training.

I'd think it's just the runners look "toned" because they're leaner than most of us. I wouldn't think they would want to lose any muscle mass they'd gained in the offseason, just because of how much defict they'd have to go into and the impact on training. I'm not sure about the endurance athletes, but middle distance and below certainly put a lot into strength training. Chris Hoy famously squats 500lbs, quoting that as a very specific 227.5kg! When I was working out how to fix my own diet/exercise regime, I was a little suprised at how much bodyfat some other (not endurance) Olympic athletes carried, but then realised it was due to wanting to be at a calorific surplus to enable returns on training effort.

We're not essentially disagreeing here. Obviously the muscle requirements of any athlete requiring explosive power are vastly different from one requiring endurance. This is why Hoy has thighs like a side of beef! Similarly sprinters need the explosive power to accelerate as much as possible as quickly as possible. Once they reach mnax speed there's not much endurance needed. And of course your typical 400m runner is a bit of a hybrid shape between sprinters and longer distance runners.

Once one gets up to a regular regime of exercise, one's metabolic rate increases, burning more calories even when resting.

I've come across people who have taken up running for weight-loss but who still fooled themselves about how much they ate (in terms of calories) and even how much running they were doing ... and expected the weight to just fall off.
I've been amazed how apparently intelligent people will diligently eat a salad lunch but ignore the soft drinks and confectionery snacks in their totals when they are assessing their intake, convinced that they are hardly eating at all.