by Types of surfaces vary in their impact on the muscles, tendons and bones of the legs, so when choosing, you should focus on your characteristics and needs. We will consider the advantages and disadvantages of the most popular places for running and draw conclusions about who is suitable for these or those.
Who should choose soil and grass?
Dirt paths and especially smooth 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 – heel pain that occurs from inflammation of the plantar fascia.
Some scientists also suggest that running on grass can reduce the overall load on the musculoskeletal 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 desired speed.
The softer and more pliable the surface you run on, the harder your feet have to be.
The structure of the lower limbs during 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 out and releases it, moving the body forward.
The stiffer the spring, the more energy it can store and release, meaning you’ll run faster and use less energy to do so.
Scientists also suggest that high stiffness may protect soft tissues — muscles and tendons — from injury. But there’s a downside: too much leg stiffness can cause stress fractures in the tibia, especially if you run a lot.
Thus, running on dirt and grass can be recommended to those who have ever suffered from plantar fasciitis and are afraid of history repeating itself, as well as to people who are overweight, which is one of the factors in the development of this condition.
In addition, running outdoors is worth choosing for those who have had experience with 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 is better off running on asphalt and concrete?
There is an opinion that hitting your feet on asphalt and concrete can damage your joints over time. So if you can’t train on dirt paths or go to a stadium with a rubber surface, it’s better to do cardio on a treadmill.
In fact, this opinion has no scientific basis.
A large review of data from more than 4,000 runners found that hard surfaces had no effect on the risk of running injuries. Training volume and past injury history were more important.
No danger was found in running on a hard surface in another scientific study involving more than eight hundred athletes.
And a study of 300 elite runners found that running on pavement was associated with a lower risk of developing Achilles tendinopathy than running on forest trails, mountain trails, or sand.
Because running on hard surfaces reduces leg stiffness, training on asphalt and concrete may protect against tibial stress fractures .
Since this condition is observed in athletes with large training volumes, it is advisable to train on asphalt for those who run a lot or have already suffered from similar fractures of the shin bones.
Who is the treadmill suitable for?
In terms of the load on the sole, the treadmill wins over all other surfaces, including grass.
If you run on a treadmill at 12 km/h, the sole of your foot will experience 26% less stress than if you do the same on the ground. And if you increase your speed to 14 km/h, it will be 31.7%.
Therefore, first of all, treadmill running can be recommended to those who have already suffered from plantar fasciitis and are afraid of a recurrence of the injury.
You can often hear that running on a track is easier than on the street. And therefore, there will be less progress. In fact, everything depends on the speed.
One study found that if you’re walking at 6.5 to 7.5 mph, running on a treadmill or on the ground is similar in terms of maximal oxygen consumption, a key measure of overall endurance.
If you increase the speed to 13.5 km/h, the track starts to lag behind in terms of load. And to equalize energy consumption, you will have to set the slope of the track to 1%, and at higher speeds – to 1-2%.
Also, running on a treadmill is somewhat different in terms of biomechanics and muscle load: it increases the frequency of steps – cadence, and provides more load on the Achilles tendon and calf muscles – the gastrocnemius and soleus.
So if you have a history of injury to these muscles, you may want to consider running in natural conditions rather than on a cardio machine.
Also, since the treadmill has a soft surface, it increases the stiffness of the legs while running. So, you should not run on it if you have suffered from a stress fracture of the bones. In addition, you should refrain from really long runs on the cardio machine.
Moreover, such training is pointless if you are preparing for an outdoor competition. Since the biomechanics of running on a track and on the ground are slightly different, having become accustomed to a cardio machine, you will run less economically on the ground. And this will certainly affect your performance.
So if you are training for a long distance race and intend to show a good result, at least part of the training should be done outdoors. Or even better – on the same surface on which the race will take place.
Is it worth combining training on different surfaces?
Based on all of the above, a combination of different types of surfaces will be the optimal choice for most healthy runners.
By running on dirt, grass, and the track, you will increase your cadence and leg stiffness, protect your feet from plantar fasciitis, and protect your muscles and tendons from overuse and injury.
At the same time, training on asphalt and concrete will give your feet a chance to be softer, which will help protect your bones from stress fractures, relieve the Achilles tendon and calf muscles, and will also help you get used to the type of surface on which most races are held.
