the one hill: mile 24 and the climb nobody expects on a flat course

By PaceKit Team · Updated April 2026

The Illinois Marathon has 85 feet of total elevation change, which is essentially flat by any standard. But at mile 24, there is one hill that multiple runners have flagged as a genuine surprise. It's a short climb, roughly a quarter mile, that arrives at exactly the point in a marathon where your legs have the least tolerance for any incline at all.

On fresh legs, you wouldn't notice it. At mile 24, after 23.75 miles of flat running, your body has calibrated to flat. Your quads, your calves, and your hip flexors are all operating in "flat mode," and the sudden introduction of even a 2 to 3% grade at this point in the race creates a sensation that feels wildly disproportionate to the actual elevation. Runners have used words like "brutal" and "unexpected" to describe a climb that, objectively, would barely register on an elevation profile.

The good news: the hill is followed by a downhill stretch that carries you toward the Memorial Stadium approach. The bad news: you have to get up it first. The advice is the same as for any late-race hill on an otherwise flat course: shorten your stride, stay upright, don't fight it, and know that it lasts less than two minutes.

The irony of the mile 24 hill is that on a genuinely hilly course (Blue Ridge, Big Sur, even Knoxville), you'd barely notice it. At Illinois, it's the only real grade on the entire course, and its isolation makes it feel larger than it is. One runner captured it well: "Even the hill at mile 24, which is the only real hill in the entire race, is over in a little over a quarter mile and is followed by a nice downhill to finish off the race." It's a speed bump on a highway. It just happens to arrive when you're 24 miles into a highway.