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Why Do Your Legs Hurt After Running? Sore vs. Injured
Runners Connect coach Jeff explains that new runners' leg soreness comes from microscopic damage caused by eccentric muscle contractions, usually peaking 48 to 72 hours after a run as part of normal adaptation. The article gives three signals to tell soreness from injury: normal soreness affects both legs, eases with warm-up, and fades after two days, while injury tends to be one-sided, one spot, worse as you run, or recurring.
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