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Are two runs the same as one?

Does splitting your run into two have the same training effect as grinding it out all at once?

Fartlek speed running training

Many elite runners do what’s known as “the double”. The double is when you run twice in one day — once in the morning and once in the evening. Sometimes the purpose of two runs is to gently increase mileage, other times it’s to shake the legs out either before or after a hard workout, and it can also help with injury prevention.

But doubling can also be great for runners who aren’t competing at the highest level. Here’s a breakdown of when the double is a good idea and when your legs need a long effort.

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The 800m-5K runner

Steve Boyd is the head coach at Queen’s University and coach of 2019 World Championship team member Lyndsay Tessier. Boyd says that middle distance runners need a lot of aerobic stimulus without depleting themselves too much. “For lots of my middle distance runners, I’ll have them run say 30 minutes in the morning and 50 [minutes] in the evening.” This is effective for runners training for events from the 800m through the 5K.

The experienced, high mileage marathoner

Boyd says that for marathoners, it depends on their mileage and experience. “For the experienced marathoner, or someone who’s running upwards of 100 miles a week, I usually have them double. It becomes too risky to have someone running over 90 minutes at a time, everyday. It leads to too much fatigue.”

Photo: Maxine Gravina

The new marathoner

If someone is new to marathoning, Boyd recommends single runs. “It’s important for new marathoners to get used to longer runs and running depleted. There are periods of the year when doubling makes sense to get the mileage up, but there should be lots of longer efforts for the new marathoner. You need to be able to do 80 minute runs in one go to run a marathon well.”

Overall, if there is a practical reason for doubling, for example, you can fit in two 45 minute runs easier than one 90 minute, then getting your mileage in is better than nothing. But on the whole, marathoners, especially those who are new to marathoning, need to get used to running for a long time all at once.

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