13/03/2026
🏃♂️ How Much Running Is Too Much? New Research Has the Answer! 🏃♀️
A massive new study of 5,200 runners published in the British Journal of Sports Medicine (2025) has uncovered when “just one more kilometer” might actually be too far.
📊 Key findings:
Increasing your running distance by more than 10% in a single session compared to your longest run in the past 30 days significantly raises your risk of injury.
The risk jumps even higher when you double your distance in one go.
Surprisingly, weekly load metrics like the acute:chronic workload ratio (ACWR) didn’t predict injury risk — meaning it’s not just about weekly totals, but about that one big run.
💡 Takeaway:
To stay injury-free, focus on gradual progress and avoid sudden spikes in your longest runs. Coaches, healthcare professionals, and runners alike can use this “single-session rule” to train smarter and safer.
Frandsen et. al. 2005. How much running is too much? Identifying high- risk running sessions in a 5200- person cohort study. BJSM