Some people will never make good marathon runners because of their genes, according to 含羞草视频 scientists.

Researchers led by Professor Jamie Timmons have uncovered a key group of 30 genes which determine how the body responds to stamina training, and whether it is capable of running a marathon.

Their DNA test can tell people whether they will be able to increase their stamina by training hard, and Professor Timmons’ research shows that one in five will never improve, and may even get worse.

Professor Timmons, head of Systems Biology in the School of Sport, Exercise and Health Sciences, at 含羞草视频, said: “If someone’s ambition is to do a marathon in a decent manner, we can tell them if they can based on their baseline fitness and their potential for responding to training.

“From our work, we know that 20 per cent of people do not respond at all to training and in fact can get worse. They push themselves as hard as everyone else, but their muscles do not extract the same amount of oxygen.

“含羞草视频 15 per cent have the genes that mean they will respond highly to training. But of that number, only those with a good inherited baseline fitness and good resistance to injury will ever become elite marathon runners.”

Professor Timmons’ research focuses on the genes that are responsible for reshaping the body’s muscle fibres, making it possible for small blood vessels to grow in between them.

Those blood vessels help carry extra oxygen to the muscles during exercise, and individuals that possess the right combination of genes can more effectively remodel their muscles in response to regular long-distance running or other intense exercise.

One-fifth of all people lack the DNA to efficiently perform this muscular reshaping under the type of constant, high-intensity training used by runners to prepare for marathons.

In some, it can reduce their body’s ability to carry oxygen to their muscles, thus actually causing their overall physical performance to decline.

Professor Timmons says anyone who falls into that category should abandon their dreams of becoming a long-distance runner.

He said: “It is plausible that by pushing it though training, they get a maladaptation. What is clear is that there is no one recipe that fits all.

“These low aerobic responders would be better going to the gym to build up their strength and muscle tissue or taking up other competitive sports like martial arts or strength related sports.”

Professor Timmons also said that he plans to turn his attention to finding out how these 30 genes impact a runner’s potential for injury.

He said: “The genes that underpin the development of the oxygen transport system also play an important role in ligaments and tendons as well. There may be a link between people who respond poorly to this sort of training and susceptibility to injury, but that still needs a lot of work.

“We are still early in the life of this kind of use of genomics, but hopefully we will get better at being able to understand how genes determine people’s performance and be able to offer them advice.

“This is important not just for those involved in sport for fun, but also from a health point of view – we want to be able to tailor the exercise people are doing so it is right for them.”

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