The first time I trained for a marathon, my IT band quit before the training plan even started.

This was 2009, building a base for Chicago. I wasn't deep into a program yet. I was running easy miles, laying the foundation you're supposed to lay before the real work begins. Somewhere in there the outside of my knee lit up. That specific, sharp band of pain that shows up at the same point in every run and then refuses to leave. I did what most runners do first, which is ignore it, and then what most runners do second, which is ignore it harder. Eventually I ended up in physical therapy.

What the PT told me didn't just stick. It surprised me. This wasn't a running problem, it was a weakness problem. I'd been running for years and had never once connected weak hips to a knee that hurt. Obvious in hindsight, the way most of these things are: the hip stops doing its job, and the joints downstream cover for it until one of them gives. Nobody had ever laid it out for me like that.

And the part that still gets me is when it happened. During base-building, at low mileage, before I'd asked my body to do anything hard. The miles didn't break me. The gap was already there. They just found it.

The work didn't look like training at all.

A lot of it was lateral hip strength. The unglamorous, side-to-side stuff that no one posts about. Hip flexor lifts. Resistance-band walks, stepping sideways until my glutes gave out. Single-leg everything, because that's what running actually is: a series of one-legged landings you're choosing to string together. And foam rolling, before and after, which felt like taking a meat grinder to the outside of my quad.

None of it was hard in the way a track workout is hard. It was tedious in a way that's harder to keep doing. But it worked, and the lesson underneath it was the useful part: running builds the engine, not the chassis. You build the chassis separately. Skip it long enough and the road lets you know.

Here's the part I didn't fully understand until I started reading for Grindstone.

In Training Essentials for Ultrarunning, Jason Koop treats downhill running as its own discipline, with different muscle recruitment, different joint angles, and different forces than running on the flat. (I go into a whole book review if you want the longer version.) A marathon on the road mostly asks your legs to do one thing for a few hours. A mountain 50k asks them to do several, and to keep doing them long after your weak links start to give.

Grindstone is roughly 5,000 feet of climbing across 31 miles. Every foot you climb is a foot you come back down, and downhill is where the damage lives: the braking, the eccentric load, the quads absorbing impact for hours. That's exactly the kind of stress that finds a weak hip or an unstable single leg. Not once, the way a hard rep does. For hours, the way a long day does.

An IT band problem at mile 8 of a road marathon is a bad afternoon. The same weak link at hour six on a mountain is a DNF. The strength work isn't a nice-to-have that sits next to the training. It's the thing that lets the training hold up when I'm tired and the trail turns down.

There's a longer game running underneath all of this, and I'll spare you the health-blog version of it.

Koop is blunt about one thing: for runners over 40, strength training isn't optional. It's how you fight sarcopenia, the muscle you lose by default as you age, and how you protect your joints and your recovery rate on the way there. I'm 45. I'd like to still be doing some version of this at 60, and the strength I build now is the strength I get to keep drawing down later. That's most of the longevity argument, and it happens to line up exactly with the injury one. Do the work now, or negotiate with the absence of it later.

Bottom line: two days a week, plus odds and ends, and a couple of honest gaps I keep meaning to close.

Upper day. Three to five sets of fifteen with a pair of 15-pound dumbbells:

Lower day. Same three to five sets of fifteen:

Grip. About five minutes, three times a week. Small thing, but poles and long descents are grip work whether you trained for it or not.

Jason Koop frames strength for runners around five movement patterns: push, pull, hinge, squat, and a carry-and-core group for the work that resists rotation. Line my two days up against that list and I cover four of them: push and pull on the upper day, hinge and squat on the lower. It's the fifth I keep letting slide.

Now the honest part, because a routine you actually skip is more useful to talk about than one you pretend to keep.

Two things have quietly drifted out. The first is the specific lateral hip work that got me out of PT in the first place: the banded walks and hip-flexor lifts. My lower day is good on single-leg strength but it's almost all forward-plane. The exact movements that fixed the original problem are the ones that fall off the moment I feel healthy. Which is, I'm fairly sure, how most people re-injure themselves.

The second is a dedicated core day. I keep meaning to add a short one and I keep not doing it. It's that fifth pattern: the dynamic, anti-rotation core work (carries, woodchoppers, that family) as opposed to the static planks I already do.

One more thing the reading clarified. My 3-to-5-by-15 scheme is on the lighter, higher-rep end. I've always lifted for lean strength, not bulk. Turns out that's close to what Koop prescribes for late season, which is roughly where I am with the race in September. What I've never actually done is his early-season version: heavier, lower reps, built in the winter base when there's room for it. So I've been running the maintenance phase of a plan whose first phase I skipped. Filing that one away for the off-season.

Strength work is the training you don't notice until it's gone. It doesn't show up in a Strava time or a long-run split. It shows up as the injury you didn't get, on the descent where your form didn't fall apart. I got the expensive version of that lesson once already, in a PT waiting room. The cheap version is just doing the work, including the parts I keep forgetting.