Staying lean: this exercise I do after every run, and in random places

I run 60 miles a week but I really, really hate gym and strength training. I’d pick a 15 mile run over 30 minutes of gym any time. I do quite a lot of interval running which probably counts as a form of strength training. But when it comes to exercising in the gym and doing dedicated strength training, I’m really lazy. I also find the dudes who pump iron unattractive, not that I, as a man, analyze the physical appeal of other men. My identity is lean and thin. My identity is being able to run a 5.30 min mile and a sub-three hour marathon. Don’t need no muscles for that!

But of course, I do understand the importance of strength training. I know that strength training can be versatile and doesn't have to be about “pumping iron”. I’m sure that one day I will start going to the gym. Maybe it will happen when I can afford a personal trainer so that I show up because there is a sense of commitment and responsibility.

However, there is one exercise from the plane of “strength training” that I’ve been doing consistently — planks. After every run, unless I’m running late for my next chore or activity, I do these three types of planks:

• A regular plank of this kind. I hold for 3–5 minutes

• Then I do side planks of this kind, 2–3 minutes; often I’d raise my arm…