Runners are obsessed with time. Whether amateur or professional, for most avid runners the goal is to get faster, constantly training to shave even just a couple of seconds off their marathon or 5K record.
This contrasts with a running trend that has begun to gain strength in recent years: slow running. The idea behind this gentle running movement is that anyone can – and should – run, regardless of their ability or how fast they run.
Supporters of this approach claim that it has many advantages, not only because we gain health, but also because of the pleasure that running at low speed produces. The interesting thing is that recent research confirms this: there is scientific evidence that running slowly can be, in some ways, more beneficial than training at higher intensity.
When thinking about elite runners like Eliud Kipchoge or Kelvin Kiptum, we might assume that to break world records, they train primarily at fast paces. Surprisingly, elite runners spend around 80% of their time training in what is called running zone 2. That is, a rhythm that raises the heart rate but is still slow enough to be able to carry on a conversation. Therefore, only about 20% of your training is done in the higher intensity zones, close to your actual race pace.
Because? The answer has to do with the stress that training places on the body. As running speed increases, the stress placed on the body increases. And the greater that tension, the greater a person’s risk of illness, infection, and injury. Hence the interest in limiting the time athletes spend training at high intensities.
But this approach is not limited to reducing the risk of injury and illness, far from it. A fundamental aspect of training is developing what is known as your “base.” In the case of endurance runners, it refers to physiologically developing a basic cardiorespiratory condition that serves as a starting point to build higher intensity adaptations.
Let’s think of a pyramid: it must have a solid base on which the rest of the structure is built. The larger the base, the higher the pyramid can be. The same goes for training: the better our foundation, the more able we are to work at higher intensities.
Our core is developed during slow running (zone 2), where physiological stress is relatively low. But even if the heart is not under much stress during the race in zone 2, the amount of oxygenated blood leaving the heart with each beat will reach (or remain close to reaching) the maximum possible volume. Higher intensities will not increase that capacity. Therefore, developing a strong core allows more oxygen per beat to reach your moving muscles, something crucial for success during the race.
Not only that: running at slow paces also causes the body to use stored fat as a source of energy, instead of relying on carbohydrate reserves from the food we eat. Burning fat is a much more metabolically efficient process, since the amount of energy derived from a single molecule of fat far exceeds the amount of one molecule of carbohydrates. This means that “slow” runners will use less energy and will be less fatigued and more able to run fast on race day.
Studies have shown that gains in VO2 max (oxygen capacity) and running speed are about 1% greater for athletes who spend more time running slowly. More importantly, the increase in aerobic base is about five times greater in slow runners compared to athletes who run more frequently at high intensity.
Even if we are not professional athletes, trying to keep most of our runs at low intensity may still be the best option.
If you want to try running slowly, the most important thing is to choose the right pace. How do we know if we are at the right speed to be considered a slow race?
Some scientists divide running pace into five or six different zones. Physiologically, zone 2 is defined below the lactate threshold, that is, the point at which lactate (an acid that the body produces when it begins to burn carbohydrates for energy, known to cause muscle soreness) begins to appear in the blood.
Simply put, this should be at a speed where we can still carry on a conversation and our heart rate is only around 70% of our maximum. If we find it difficult to maintain a conversation, it is advisable to reduce the pace.
Running slowly offers many benefits, both for the body and mental health. So if you’ve always been shy about running slowly, maybe this will encourage you to put on your running shoes and go for a run.
