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- Issue 94
- How much running is too much?…
How much running is too much? Identifying high-risk running sessions in a 5200-person cohort study
Key Points
- Spikes in running distance are thought to contribute to injuries, but there’s little consensus on how best to quantify these spikes.
BACKGROUND AND OBJECTIVE
Despite the proliferation of wearable technology for runners to monitor training loads (1), misapplication of load likely remains a key contributor to high running injury rates (2). The primary error is thought to be spikes in running distance (i.e. “doing too much too soon”). Yet within the running community, there’s little consensus on precisely what constitutes a spike.
For decades, runners have been advised to follow the “10% rule” by avoiding week-to-week increases >10% (3). More recently, the acute-to-chronic workload ratio (ACWR) has gained popularity (4). Based on the ACWR, runners have been cautioned to avoid increases of >50% in the current training week compared to the previous month’s average.
With both the 10% rule and the ACWR, the typical numerator of the calculation is the current one-week training window. However, recent work suggested a single long-distance training session (compared to the previous 30 days) may be a more relevant exposure (5). This study investigated the associations between these metrics for distance spikes and running injuries.
In order to minimize risk, runners may want to prioritize small increases in distance relative to their longest run in the previous 30 days.
METHODS
A total of 5205 runners participated in a 1.5-year prospective study. The runners were an average of 46 ± 10 years old, 78% male, and predominantly North American and European, with a median of 9.5 years of running experience. All