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Training for a marathon? This is why professional athletes have an edge

Preparing for a marathon is no easy feat. But what happens to your body when training? Dr Richard Bruce explains there’s more to it than just running.

Athletes have bigger hearts

Just like arm or leg muscles will increase in size with weightlifting, the heart muscle will grow with endurance training. The walls of the heart become thicker, and the chamber size increases. This gives the heart a greater capacity to pump blood throughout the body and deliver more oxygen to the working muscles. However, these changes will take months or years to occur.

Dr Bruce says: “An endurance athlete will have a resting heart rate of between 30-40 beats per minute compared to an average person, who might have 60-100 beats per minute. As the athlete’s heart is larger, it will not need to beat as often to deliver the same blood flow. One simple way to test for cardiac adaptations with training is to monitor your resting heart rate over time.”

Training also increases the number of red blood cells in the vessels. These cells carry and deliver oxygen to the various tissues of the body, including muscle. Alongside changes to the heart, an increase in the number of red blood cells will allow more oxygen to be delivered to the muscles during exercise, which is beneficial on race day.

Training will literally change your muscles

Training will increase the production of mitochondria (the powerhouses of the cell) in a runner’s leg muscles. Mitochondria are where sugars and fats are burned with oxygen to produce energy the muscle use to contract and enable a person to move. Training also allows the muscles to become more efficient at using oxygen, meaning a runner can run for longer at higher speeds.

These changes won’t happen overnight. The average professional runner might run over 100 miles in a week, and these adaptions to the body will take place over months of regular training. These transformations can still occur with less intensive training workouts, so novice runners should keep training.

The reasoning behind blood doping

The King’s Drug Control Centre (DCC) is the only World Anti-Doping Agency (WADA)-accredited lab in the UK and analyses between 10,000 and 12,500 samples from athletes a year, testing for prohibited substances.

“There are many prohibited substances that can enhance difference aspects of an athlete’s physiology or performance. For endurance athletes like marathon runners, some substances like synthetic erythropoietin (EPO) can help develop more red blood cells, so you will have a greater ability to deliver oxygen to your muscles when running. In the past, athletes have used blood transfusions to also increase red blood cell number. But all these practices are prohibited, and the excellent work of WADA and King’s DCC help to ensure fairness across different sports.” – Dr Richard Bruce, Senior Lecturer in Cardiorespiratory Physiology

Could virtual reality change how we view exercise?

Dr Bruce and his colleagues are using virtual reality to see whether it might change psychological perceptions to exercise. The team, in collaboration with Oxford University, is developing a virtual environment to see if they can enhance the efficacy of rehabilitation programmes. As many patients with chronic disease are exercise intolerant, changing people’s perceptions of exercise by manipulating virtual reality settings might encourage them to do more.

In the project, volunteers are cycling up and down hills in a virtual reality environment.

Dr Bruce said, “We know people are a bit more motivated to exercise when they do it in virtual reality. We can make the hill look more or less steep, or make it seem like you’re going along the road more quickly or more slowly. We want to see if the manipulation of reality can change how it feels to exercise, and make it seem more or less difficult.”

“We’ve just started to test some young healthy people, but the long-term plan is to test the concept with breathless patients who are exercise intolerant and undergoing rehabilitation programmes. Can we change how they perceive exercise? That’s the key question.”– Dr Richard Bruce, Senior Lecturer in Cardiorespiratory Physiology

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Richard  Bruce

Richard Bruce

Senior Lecturer in Cardiorespiratory Physiology

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