Why does the risk of stress fractures increase disproportionately with small increases in running mileage on asphalt compared to a soft track?

💡 Explanation

The risk increases due to bone's response to stress. Wolff's Law describes bone remodeling, where bone adapts to mechanical stress. Higher impact forces on asphalt, as opposed to a soft track, lead to greater stress exceeding the bone's adaptive capacity, causing micro-fractures to accumulate; therefore, stress fractures become more likely on asphalt, rather than from metabolic waste or glycogen depletion alone.

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