By Olivia Trani  

When it comes to preparing for a marathon, the prevailing philosophy has been that steadily increasing your training volume – such as weekly running mileage and cross-training workouts – leads to better race outcomes. However, a new study published in Sports Medicine suggests that, in some ways, less is more. 

By analyzing training trends of Boston Marathon runners, a research team led by Virginia Commonwealth University and Harvard Medical School found that building a strong running foundation up to a year ahead of time – and then strategically reducing training volume a few months before race day – was the stronger indicator of having a faster finish time. 

“There’s a misconception that more is always better, but our findings show that tapering is actually a really important part of the overall training portfolio,” said Alexandra F. DeJong Lempke, Ph.D., an assistant professor in the VCU School of Medicine’s Department of Physical Medicine and Rehabilitation and lead author of the study.  

How did you analyze marathon training trends? 

Our research team looked at data collected from more than 900 runners from the 2022 Boston Marathon to see how their training programs in the year leading up to the race impacted performance. Through surveys, we analyzed each athlete's weekly mileage, hours spent running and the frequency of their runs. We also assessed how often runners included speed-specific workouts and cross-training sessions (like weightlifting, non-impact cardio or core-strengthening workouts) into their training plans.  

Our team divided their analysis into two time periods: 12-4 months and 4-0 months before the marathon. The 12-4 months period reflects the athletes’ long-term running habits, while the 4-0 months period is when runners typically focus on training for the marathon. We did not measure the two weeks before race day, which is when athletes tend to decrease the number of miles they run. 

What long-term running habits improve marathon performance? 

Building a strong running foundation 12-4 months before race day is a key factor for improving marathon performance, according to the data. Athletes who logged more training hours each week during this time period were more likely to have faster race times on marathon day. 

Performance enhancing training habits 12-4 months before a marathon include:  

• Putting in hours now will shed minutes later. Running 10 hours or more a week was linked to better performance than 5-7.5 hours, which in turn was better than 2.5-5 hours. 
• Run more miles and complete more sessions each week. With every additional running session per week, runners shed about 3 minutes from their race time on average, and every additional kilometer ran per week shaved 30-40 seconds off marathon times on average. 
• Focus on building speed, rather than cross-training. Additional running workouts focused on speed and endurance (like intervals, hills, fartleks or tempo runs) each week helped runners shed about 16 minutes on average off their race time. However, the frequency and duration of cross-training sessions completed during this time period did not influence their race times. 

What training factors are the most important leading up to the marathon?  

Training trends from the 12-4 months period are still important in the 4 months leading up to the race, with a few key tweaks.  

Maintaining a high training volume and adding speed-specific workouts were still associated with faster race times, but gradually reducing training sessions could actually improve performance on race day. Runners can afford to spend less time training at a high frequency because they’ve already built up their muscles and endurance over the course of several months. By slightly tapering, pumping the brakes a bit, runners’ bodies are able to rest and recover in the weeks leading up to a marathon.  

Beneficial training habits in the 4 months before a marathon:  

• Reduce running sessions. Runners who ran fewer weekly sessions during this period compared to what they ran 12-4 months ago were on average 3 minutes faster than those who maintained or increased running frequency.  
• Do more cross-training. Cross-training sessions are also more influential to running performance during this window, with each extra session logged per week shedding 6 minutes from the marathon time.  

In short: How can runners improve their marathon race times?  

Building a strong base in the year leading up to a marathon, then dialing back on running frequency in the months before the race, might be key for finishing with a faster race time.  

Runners can do a big service to themselves by not running their bodies into the ground. When they develop a strong foundation for endurance running ahead of time, they can afford to slightly reduce your training load in the months leading up to the marathon. By doing so, they’re giving their body adequate rest and recovery to be able to optimize their performance on race day. 

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