[arghnoname]

I'm on the heavy side for a distance runner, but compared to the general population, I've never been very heavy or very light (BMI currently around 26). I mostly run longer distances (a half marathon most weeks, lots of six mile runs, full marathons and the distances to train for them about twice a year).

In my experience, qualitatively, what you say is absolutely true. I don't even notice a change in pace if my weight floats up or down a bit, I mostly run at a specific level of effort and the pace adjusts itself depending on how much I've over-indulged. However, there are thresholds.

If I try to run a pace that is too slow, there's a point where it almost becomes more shuffle than run, gait goes to hell, and there's a loss of efficiency. As I've gotten more fit (but not lighter) I can now do zone 2 running on the flat with workable form, but this wasn't always the case. It's still less efficient than a fast pace, but at least it looks like running.

So if one is too heavy to even run with actual running form for any length of time, it's harder to be heavy. That's okay, they should probably try run/walk intervals until they get there.

On the other hand, it can also be harder when you're more fit. My pain tolerance has gone way up. I can just beat the ever living snot out of myself, and if I'm not careful, I do just that. It's much easier to do too many miles way too quickly now and that starts manifesting itself in all kinds of noisome ways. Find anyone who considers themselves a runner and get them talking about their injuries and you better not have anywhere else you need to be.

[hinkley]

I got up to half marathon walking distance at a little over 3 hours for six weeks this summer, and have been in PT ever since. 'Too hard' doesn't necessarily manifest the day you make the mistakes. It could be weeks later.

[chrisfosterelli]

Yes, I agree. I mentally consider "running" to include "walking, if that's the speed you should be at for your target intensity". I do a lot of walking on my runs even still :)