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What determines marathon performance?

Researchers look at which factors are most likely to affect your finish time on race day

After a year-long absence, most of the World Major Marathons, as well as several other races, are finally back, and thousands of Canadians are getting on start lines again. Many of these runners have been training for months in the hopes of setting a new personal best, but how can they know if they really have a shot? Recently a group of researchers analyzed training and racing data from 260 people at the Dublin Marathon to find out which variables have the biggest impact on marathon performance, and some of the results might surprise you.

Scotiabank Calgary Marathon. Photo: Dave Holland

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The study

The authors of the study administered a self-report questionnaire to 260 participants at the 2018 Dublin Marathon, asking them questions about their anthropometrics, training behaviours and recent race times. They then cross-referenced their race numbers with their split times and finish times to determine which factors had a greater effect on the runners’ results.

The results

Perhaps not surprisingly, the researchers found that the greatest determinant of marathon performance was the athlete’s training history. Training variables including weekly mileage and average running pace during training all appeared to be associated with eventual finish times. The authors point to the “Theory of Collapse”, which suggests that the point at which runners break down in a race will be approximately one-twentieth of their total mileage in the previous eight weeks. They note there is little empirical data to support this theory and conclude that runners “need to carefully plan their training schedule to ensure that they reach their necessary mileage in a safe timeframe.”

The Halifax Road Hammers race at the Valley Harvest Marathon in Nova Scotia. Photo: Instagram/hfxroadhammers

The researchers determined that the second-most prominent predictor of marathon performance was how pragmatic runners were about their goal finishing times. They found that runners with more aggressive (and arguably less realistic) goal times were more likely to finish slower than those with more realistic goal times based on their performance in training and previous results.

Pacing, by extension, is also a strong predictor of marathon performance, because runners with more aggressive targets are more likely to go out too hard at the beginning and have to eventually slow down. Since the researchers found that runners with more even splits throughout the entire race typically finished faster than those who had more divergent split times kilometre over kilometre, this association makes sense.

Photos from the M2M booth at the 2019 Toronto Waterfront Marathon Expo in Toronto, ON Canada.

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The bottom line

Of course, there are many different variables that will affect your performance on race day, such as nutrition before and during the race, weather conditions and injuries, to name a few. Still, this study reiterates the importance of proper preparation, having an appropriate goal and creating a race-day pacing plan if you want to meet your target finish time.