As you know, most running shoe manufacturers highly recommend changing your running shoes every 700 to 1,000 km on average. That is, if you run 100 km a week, after two months you throw out your running shoes and go to the store to buy new ones.
Every runner, at least once, has thought – is it too often? It’s not a packet of spaghetti: good running shoes cost good money, whether it’s trail or pavement, whatever.
In this regard, there are runners who run several thousand kilometers in one pair of shoes. Are they right? In some cases, yes. There are several reasons to balk at the recommendations of sneaker vendors.
1. Manufacturing companies must sell. And not just sell, but increase turnover in any way possible. This is an elementary law of marketing. However, it is advisable not to confuse cause and effect. The use of ultra-light, but not too expensive and not too wear-resistant materials is dictated by consumer demand, which plays into the hands of brands.
2. Underestimating the real life of running shoes is a kind of reinsurance by companies in the form of protection from liability – “well, we warned…”.
3. technical runners and representatives of various “barefoot” schools of running are not particularly interested in the fact that the shock-absorbing properties of all kinds of shock-absorbing inserts and, especially, the sole itself, decreases over time.
4. Many marathon runners do not need additional support (which is also subject to wear and tear) if pronation is not abnormal and the landing is on the forefoot.
All this is true for half the runners and triathletes, but what about the other half of the athletes who run with a hard landing on the heel, whose only protection is the cushioning of the sneaker?
Some will rush to suggest retraining and changing running techniques, but such ill-considered recommendations can do more harm than good. And it is possible that the athlete, while learning the “right” technique, will begin to injure himself. This is despite the fact that the athlete did not know any problems before and enjoyed running.
The more logical option, of course, is to keep an eye on the wear and tear of sneakers. Today the main material for the sole is ethylene vinyl acetate, or more simply, EVA (EVA) foam. It plays a crucial role in the cushioning of the shoe, not gels, air and other commercial chips of Nike, Asics and Brooks.
Loss of cushioning of the outsole
The EVA sole has a light and flexible structure, which under the influence of constant compression loads tends to compact, leading to a partial loss of the original cushioning properties.
But ethylene vinyl acetate currently has no competitors because of its weight, resistance to aggressive substances and high temperature, hygienic and cost.
On almost all sneakers the compaction of the sole material can be visually detected by the appearance of horizontal wrinkles and creases. But the fact is that EVA does not compact indefinitely. The maximum loss of cushioning properties is about 40%. The average mileage in this case is around 800 km. Then the compaction of the sole practically stops.
The top runners had even less losses in sole depreciation – about 20%. And the growth of losses stopped after ~1000 km, remaining at the same level.
In fact, it turns out that the manufacturers recommend that we change the sneaker exactly when the EVA sole reaches the threshold, when the reduction of cushioning no longer occurs. It turns out that runners who continue to train in “worn out” sneakers and have no related problems, do not lose anything.
In fact, even if the cushioning properties of the shoe continued to decrease smoothly and gradually to zero, this process would be difficult to notice because of the body’s ability to adjust quite imperceptibly to external conditions, which include the stiffness or unevenness of the running surface.
The rigid surface itself has only a negligible effect on the stressful impact loads and is practically not a provocateur of injury. Because initially the musculoskeletal system is able to successfully compensate for everything.
However, it is the addiction to overly soft shoes that creates too warm conditions for the feet, dulling and weakening the body’s ability to work efficiently and safely on any surface.
Гиперпронаторы
Некоторые исследования, объявляющие поддержку стопы бесполезным излишеством, на данный момент не являются убедительными на сто процентов. Для бегунов, приземляющихся на передний отдел стопы, это разумно. Но когда идет речь о приземлении на пятку или на плоскую стопу, то отсутствие поддержки вызывает дискомфорт у гиперпронаторов. Поэтому пока что не будем от нее отказываться.
In these models of running shoes there is a support for the foot from excessive torsion of the ankle and its collapse inward. It is usually made of the same EVA and looks like a wedge-shaped insert in the area of the arch of the foot.
As the material, both the sole and the additional support, compacts and sags, the ankle can increase the amplitude of movement and affect the mechanics of running. This sometimes causes pain in the lower back, knees and other critical areas.
But in this case you can often get out of it not by changing your sneakers to new ones, but just by buying anatomical insoles with a more pronounced arch support.
The brands are
Manufacturers actively promote their know-how in the form of a variety of cushioning inserts in the sole. But the shoe models, which are the same for the same purpose, in practice do not have a huge difference in cushioning properties. Because the basic material of the sole in all is the same – ethylene vinyl acetate. And the final impact loads are regulated by the runner’s body.
You should not look at whether there is a drop of gel somewhere under the heel, but at the personal sensation and comfort of your foot. And also on the fact that the sneaker does not radically change your biomechanics. And also on a few more important parameters.
Чередование кроссовок
That’s right, a competent runner has more than one pair of sneakers, and while one is on their feet, the other is resting and ventilating at that moment. This is good in terms of hygiene and the ability to run in all conditions, from asphalt to skyrunning. However, it does not help at all to reduce the deformation and compaction of the EVA foam. At 700-1000 km run it will reach the minimum values of cushioning properties just the same.
Минимализм
Those who like minimalist running shoes that have no need for cushioning are, in a sense, saving on equipment, because they can run in sneakers until they fall apart thoroughly or their soles are worn through. If these shoes are well-made, they are truly indestructible and do not need to be replaced often.
Statistics
According to a survey of a wide range of runners I know, about half of athletes stop using running shoes for their workouts only when they wear out so much that they just can’t hold their shape. By the way, many often do so even before the manufacturer’s stated replacement time.
About 20% of marathoners and triathletes rely on their bodies to tell them through back pain or joint pain to go shopping for an outfit.
The remaining 30% of athletes are those who follow the manufacturer’s instructions and do not hesitate to change shoes.
What to do?
Undoubtedly, it is necessary to change running shoes. This becomes most relevant when there are musculoskeletal features, when wear and tear physically affects the health of the body.
Also remember that wear and tear is not only a loss of cushioning or holes in the mesh or in the butt, which has long been no one pays attention to, but including the uneven grinding of the sole surface, which can affect the placement of the foot and change the way the joints work.
But at the same time we should not forget that the main purpose of any shoe is simply to protect the feet from an aggressive surface. Therefore, many statements directly related to commercial benefits should be treated with skepticism and try to understand the details. Although, if the budget allows, it is possible to dress up.
