On 12th April 2026, I will be running the London Landmarks Half Marathon, raising money for Pain Concern. It might seem like an odd choice for someone who spends much of her professional life helping people reduce pain. Considering I haven’t run this far since 2013, why voluntarily induce sore calves, tight hips and the particular existential negotiation that occurs around mile eight? Because training for a half marathon is a living laboratory in how the brain interprets sensation. And that is precisely what persistent pain is about. Pain, Prediction and the Protective Brain When we run long distances, discomfort is inevitable. The muscles fatigue. Breathing deepens. The body signals effort. But what determines whether that sensation feels manageable or alarming is not the tissue…