The types of covering differ in their effect on the muscles, tendons and bones of the legs, so when choosing, you should focus on your own characteristics and needs. We will look at the advantages and disadvantages of the most popular places for running and draw conclusions for whom one or the other of them is suitable.
Who should choose soil and grass
Dirt paths and especially flat short grass are softer than asphalt and concrete. Running on such a surface puts less stress on the foot, which in the long run can protect against plantar fasciitis — pain in the heel caused by inflammation of the plantar fascia.
Some scientists also suggest that running on grass can reduce the overall load on the locomotor system and increase the efficiency of the exercise.
The fact is that when running on different surfaces, the body automatically adjusts the stiffness of the legs to maintain the required speed.
The softer and more pliable the surface you run on, the harder your legs have to be.
The structure of the lower limbs when running is often compared to a spring. When you step on your foot, the spring compresses and stores mechanical energy. And when you push off the ground, it straightens and releases it, pushing the body forward.
The stiffer the spring, the more energy it can store and release, which means you will run faster and spend less energy on it.
In addition, scientists hypothesize that high stiffness may protect soft tissues – muscles and tendons – from damage. But there is a downside: too much stiffness in your legs can cause tibial fatigue fractures, especially if you run really hard.
Thus, running on soil and grass can be advised to those who once suffered from plantar fasciitis and are afraid of repeating history, as well as to people with excess weight - one of the of factors in the development of this condition.
In addition, running in nature should be chosen by those who have experienced muscle and tendon injuries. But it is worth considering that when preparing for a race that will take place on asphalt, it is worth at least sometimes going out on this surface.
Who prefers to run on asphalt and concrete
There is an opinion that hitting the feet on asphalt and concrete can eventually damage the joints. So if it is not possible to train on dirt paths or go to a stadium with a rubber surface, it is better to do cardio on a treadmill.
In fact, such an opinion has no scientific basis.
In a large-scale review of data from more than four thousand runners, they found that a hard surface had no effect on the risk of injury during running. Much more important is training volume and past injury history.
They did not find the danger of running on a hard surface and in other scientific work with the participation of more than eight hundred athletes.
And a study of 300 elite runners concluded that running on asphalt had a lower risk of developing Achilles tendinopathy than running on forest and mountain trails or sand.
Since the stiffness of the legs is reduced during running on hard surfaces, training on asphalt and concrete can protect against a tibial fatigue fracture.
Since this condition is observed in athletes with large volumes of training, it is possible to advise classes on asphalt to those who run a lot or have already suffered from similar fractures of the lower leg bones.
Who is suitable for a treadmill?
In terms of stress on the sole, the treadmill beats all other surfaces, including grass.
If you run on a track at a speed of 12 km/h, the sole of your foot will feel 26% less stress than if you do the same thing on the ground. And if you increase the speed to 14 km/h - by 31.7%.
Therefore, first of all, running on the track can be advised to those who have already suffered from plantar fasciitis and are afraid of repeating the injury.
You can often hear that running on a path is easier than running on the street. Therefore, there will be less progress. In fact, it all depends on the speed.
One study found that if you're moving at a speed of 10.5-12 km/h, running on a track and land match for maximum oxygen consumption, a key measure of overall endurance.
If you increase the speed to 13.5 km/h, the track begins to lag behind the load. And in order to equalize energy consumption, you will have to set the inclination of the canvas by 1%, and at higher speeds - by 1–2%.
Also, running on a track is slightly different in terms of biomechanics and muscle load: it increases the frequency of steps - cadence, and ensures more load on the Achilles tendon and the calf muscles - calf and soleus.
Therefore, if you have already had damage to these muscles, you should consider running in natural conditions, and not on a cardio machine.
Also, since the track has a soft surface, it increases the stiffness of the legs during running. Therefore, you should not run it if you have suffered from a fatigue fracture. In addition, you need to refrain from really long runs on cardio machines.
Moreover, such training does not make sense if you are preparing for an outdoor competition. Since the biomechanics of running on a track and land are slightly different from each other, once you get used to a cardio machine, you will run less efficiently on land. And this will probably affect your performance.
Therefore, if you are preparing for a long-distance race and intend to show a good result, spend at least part of your training in the fresh air. And even better - on the same surface on which the race will take place.
Should you combine training on different surfaces?
Based on all of the above, it is the combination of different types of coatings that will be the optimal choice for most healthy runners.
Exercising on the ground, grass and track, you will increase the cadence and stiffness of your legs, protect your feet from inflammation of the plantar fascia, and muscles and tendons from overuse and injury.
At the same time, by arranging training on asphalt and concrete, you will give your legs the opportunity to be softer, which will help protect bones from fatigue fractures, relieve the Achilles tendon and calf muscles. And this way you will get used to the type of surface on which most of the races are held.