Home > Beginners

All about that base! Making the case for aerobic base building

It's all about that base--building. Building a solid base by running mostly easy is the surest way to set yourself up for future running success.


How many times have you overlooked the importance of building up your base fitness? Probably more than you think!

All runners—regardless of age, ability or preferred race distance—should start a new season or cycle of training by building a solid aerobic base. This is done by running easy for several weeks or months with very little, if any, added intensity.

RELATED: Why you should schedule a post-race recovery phase after a season of training

That means that the focus is less on workouts and more on just getting in your mileage day after day.  “Base building is a time to take a break from racing and fast workouts, and slowly build up the amount of running volume you do,” says John Lofranco, coach of the McGill Olympic Club.

When do I start building up my base?

Generally, the base building phase begins after a few weeks off or away from training. Usually, that’s after finishing last season’s goal race. Typically, base building will last for at least three to four weeks or, according to Lofranco for as long as possible. Base building could even last as long as two to three months.

How runners benefit from base building

While just running easy may seem boring or ineffective to some, it offers several significant and unique benefits.

As long as you build up gradually, it is by far the safest way to increase your mileage over time given that easy running places much less stress on the body than workouts do. “The reason intensity is avoided during the base building phase is to allow the runner to do more volume and be better and fully recovered for a subsequent training cycle,” says Lofranco.

From a scientific point of view, easy running is also the most effective way to build muscle mitochondria which are the energy-producing “powerhouses” of every cell in the body. The more mitochondria you build, the better you’ll be at generating energy. It also means you are prepping your body to benefit later on when doing higher intensity training. If you build them first (with easy running), then improve them later (with hard running), you’ll end up with an increased ability to run fast aerobically, which is essential for every race from 5K to the marathon.

All of this might sound great–until you put it into practice. Some runners struggle with keeping to an easy pace. For those who get a bit eager with only running easy, Lofranco suggests adding strides—short accelerations of 80-100m or 20 to 30 seconds—a couple times a week after a routine easy run.

RELATED: Add strides for a boost of additional speed

Lofranco fears that base building and it’s importance in training seems to have fallen by the way-side. “Some runners seem to train and race nearly every week and weekend, year-round,” he says. “There is a kind of FOMO (fear of missing out) regarding workouts too. Runners worry that if they don’t do workouts for three months, they are going to get slow.”

However, if runners spent those same three months running more than they have ever run before, they’ll be better prepared to do those workouts (and races) when they’re ready.