Exercise Science Study Finds Running Is Both Good and Bad for You, Depending on the Day

A comprehensive meta-analysis published in the Journal of Exercise Science has concluded that running is simultaneously beneficial and detrimental to human health, depending on which of the 847 included studies one chooses to believe. 'Running prevents cardiovascular disease,' said lead author Dr. Alan Pronation, scrolling through a spreadsheet. 'Also, running causes cardiovascular disease. Running builds bone density. Also, running destroys bone density. Running improves mental health. Also, running makes you anxious because you're always thinking about running.' The analysis, titled 'Is Running Good? A Systematic Review of the Contradictory Evidence,' compiled every peer-reviewed study on recreational running published between 1970 and 2025. The results were, as Dr. Pronation described them, 'a perfect mess.' 'For every study showing that 30 minutes of daily running reduces mortality risk by 27 percent, there's another study showing that 30 minutes of daily running increases injury risk by 34 percent,' he said. 'The net effect is that you live longer but in worse condition, or you live shorter but feel great, or neither, or both.' The journal's editorial board published an accompanying commentary noting that the meta-analysis 'raises more questions than it answers, which is the opposite of what we asked for.' Public response has been predictable. Runners cited the positive findings as vindication. Non-runners cited the negative findings as justification. Both groups accused the other of cherry-picking, which Dr. Pronation confirmed is 'exactly what the data invites you to do.' Dr. Pronation's recommendation, buried in the paper's final paragraph, states: 'Individuals should consider running if they enjoy it and not running if they don't, as the evidence supports both decisions equally.' He has received four hundred emails calling this recommendation 'unhelpful.'