“Competitive and amateur sports are equally affected. It’s about relative overload,” Carsten Hollander tells DW. “For example, you sign up for a spring marathon on New Year’s Eve and train 20, 40 or 60 kilometers per week without doing anything else – these are high-risk moments. A competitor after four The same can happen with runners after a week’s break – for example, a college runner who returns to high-intensity training too quickly after a semester break.” (Also read: What is stress and what effect does it have on our body?)
Holländer is professor of sports medicine at the Medical School Hamburg and has also been the head doctor of the German Athletics Association (DLV) since January 2024.
“In my career as a middle-distance runner, I have only survived one low-grade stress fracture,” revealed the sports physician, who has been researching this type of injury since his studies.
gradual process
A classic fracture occurs when a force, for example a blow or kick, suddenly impacts the bone from the outside. In contrast, stress fractures – often called fatigue fractures – occur at the end of a gradual process. That’s why scientists also talk about “bone stress injuries,” which include anything from edema – a painful accumulation of fluid in the bone – to fractures.
“Usually the pain is already there at the beginning of the race and it gets worse so that you can’t run until the end of your route,” says Hollander, who is alert to the alarm signs indicating a possible stress fracture. Let’s describe. “For example, this is different from tendon injuries, which may not be as painful after the warm-up phase as they were at the beginning.”
If you feel a dull or pulling pain in the bone while running, you should consult a doctor. The main areas at risk when running are the shins and feet.
Most cases in running sports
Stress fractures can occur in any type of sport, and bones that are subjected to high stress are at particularly high risk. For example, fatigue fractures occur more often in the ribs of rowers or golfers, in the bones near the elbow or wrist in tennis, and in jumping sports such as basketball, the bones of the leg as well as the foot and knee joints are more frequent. Are affected. , In weightlifting and gymnastics, the vertebral arch is particularly at risk.
However, most stress fractures are reported in running sports. “On the one hand, racing is a very popular sport in Germany, in which 18 to 20 million people participate. This results in a large number of cases. On the other hand, the impact forces occurring at the time of landing are an important factor in bone-strain Injuries,” explains Hollander.
Female athletes are at greater risk!
According to studies, the risk of stress fractures in women is almost double that of men. There are several reasons for this. Firstly, women often have lower bone density and secondly, hormone levels.
“Estrogen [female sex hormones] “Bones are important for metabolism,” explains sports physician Hollander. The type of contraceptive may also play a role: to what extent does the preparation interfere with metabolism?”
That is why sports gynecologists are also now part of DLV’s medical network. Additionally, eating disorders are more common in female athletes than in male athletes and such disorders also increase the risk of stress fractures. “Very low relative energy intake should be avoided at all costs,” says Hollander.
enough calcium, but not too much
To prevent stress fractures, athletes should ensure that their bodies have an adequate supply of calcium and vitamin D. Calcium stabilizes bones, while vitamin D ensures that calcium is better absorbed by the body and incorporated into the bones.
While you usually have an adequate supply of the “sun hormone” vitamin D when playing sports in the summer months, calcium must be added to the body. As a rule, the daily requirement of approximately 1000 mg of calcium can be easily met with a healthy diet, for example with dairy products, vegetables or calcium-rich mineral water.
“Vegetarians or vegans who use milk alternatives should be careful. Some contain calcium and some contain no calcium,” explains Hollander. Scientists warn that even though calcium is excreted through sweat during intense training, you should not mindlessly reach for calcium pills to compensate for the deficiency.
“Taking too much calcium can also be dangerous. Among other things, it can increase the risk of kidney stones.”
increase training gradually
Since stress fractures are the result of overloading the bones, Hollander recommends sensible training management.
“You should not increase your workload by more than 20% from week to week. This applies to the total distance covered per week, the length of the longest race, but also to the intensity and scope of the individual race intervals “
Fitness apps on your smartphone or smartwatch can help you track your exertion. Biomechanical analysis also can’t do any harm. After all, your individual running style also determines how much stress is placed on your bones.
“A higher frequency, i.e. smaller steps, is deterrent. Then the load per step is less,” says Hollander.
And if a fatigue fracture occurs? Then the top priority is to protect the affected bone. Unlike “classic” fractures, the broken bone parts in stress fractures rarely move. Therefore it is usually not necessary to completely immobilize the bone with a plaster cast. It is even possible to play the game, albeit in a different way.
“For passionate runners, taking a break from the sport is usually the last thing they want to do,” says Hollander. “They are more likely to switch to cycling or aqua jogging.”
This article was originally written in German.
