Why some elite athletes have a greater risk of developing a motor neuron disease – and what are we doing with it

Motor neuron disease (MND) is a destructive condition that causes progressive muscle weakness by damaging movement neurons, nerve cells connecting the brain with muscles. These neurons allow us to move, breathe, eat and finally stay alive.

Unlike many chronic lifestyle conditions, in which “unhealthy” increases the risk, MND does not comply with ordinary rules. In fact, some of the highest profile cases of MND in recent years concerned elite athletes: Rugby legends Doddie Weir AND Rob Burrow They are two well -known examples. Previous Research from Italy An increased incidence of MND in former professional players was also found.

But wait – they are elite athletes. Hearty. We always say that exercises protect against heart diseasestroke, diabetes and many forms of cancer. So why would this be related to something as destructive as MND?

This is the question that we study in Sheffield Institute for Translational Neuroscience (Sitran)Part of the University of Sheffield, where we examine how tiring physical activity can play a role in triggering MND.

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One of the first questions we asked was whether this link could simply be delayed bias of survival. In other words, do people who practice more develop MND only because they are protected against more common causes of death?

To examine this, we turned to genetics. In particular, we looked at the relationship between MND, exercises and genetic mutations – DNA changes set from birth and does not affect your lifestyle or survival.

We found That a miniature percentage of people who are genetically predisposed to get involved in a high level of physical activity also has a genetic risk for MND, but only when it comes to very intensive anaerobic exercises. Other forms of exercise, such as weightlifting, had no influence. Most importantly, this link seemed to be independent of the head injury, which has also been suggested How Potential cause of MND related to exercises.

How much is too much?

It is crucial to emphasize that most athletes never develop MND. There is no plain one -to -one relationship between intensive exercises and the disease.

What we observed Our genetic examination was the result of the dose; The risk was observable only in people performing an extreme level of activity, for example over 12 hours of intensive exercise per week. Even then, most did not develop MND. But in this group the risk of MND was higher than in the general population.

It echoes arrangements from a Swedish study The involvement of cross -country skiers who took part in Vasaloppet, an exhausting 90 km race. The fastest skiers, those at the top of the performance spectrum, were four times more exposed to MND development than the general population. However, the skiers who finished in the middle of the package had a 50% lower risk than the average.

Why? We believe that extreme levels of physical activity can turn off protective mechanisms in motor neurons. These mechanisms act as safety switches, preventing neurons and wear from viewing. Turn them off and you can improve performance-but at potential long-term costs. We are currently examining whether we can reactivate these safety mechanisms to prevent or delay the beginning of MND.

To develop treatment methods, we first need a reliable model of the disease – and there are fruit flies. We have flies that carry a known genetic risk factor for MND.

In vigorous flies, exercise improves strength and extends the vitality – just like in humans. But in flies susceptible to MND, the opposite does the opposite: it makes them weaker and accelerates the loss of motor neurons. We saw Similar patterns in human research.

We are now testing interventions that could protect against this damage. Early results suggest that the key may consist of adjusting electrical signals between motor and muscle neurons; potentially allowing us to keep the benefits of exercise while eliminating the risk.

Should athletes worry?

There is no need for alarm, only awareness. Exercises are mostly beneficial and should be encouraged to almost everyone. Most professional athletes remain in exceptional health throughout their lives.

But for a miniature part of people, extreme anaerobic training can have a hidden risk. By identifying these people early and better understanding of basic biology, we try to develop targeted prevention and treatment strategies – without discouraging the countless benefits of dynamic life.

Science is still developing. But the goal is clear: make sport safer and the disease of the motor neuron is rarer.