As the bodily systems improve with exercise the amount of oxygen the body needs will increase. This is provided by the lungs which also improve during exercise. The main benefits of exercise on the respiratory system are:
- The muscles around the ribs become more efficient, making breathing more efficient.
- The amount of air the lungs can take in will increase.
- Because the surface area of the lungs has increased, more oxygen can be transferred from the air in the lungs to the blood capillaries.
So if I exercise properly does this mean I will win a marathon?
No, however much we exercise, some people are born better marathon runners then others. No matter what your build is or how much stamina you have got, if you don’t have the right type of muscle fibres then the chances of you become a world class runner are extremely slim. Muscle tissue is composed of muscle fibres that contain two main fibre types, which contract at different speeds, fast twitch fibres which contract quickly and powerfully but fatigue quickly and slow twitch fibres which contract slowly and can keep going for a long time without getting fatigued. Most people will tend to have a balance of about 50% of these two types of fibres in their muscle. Experiments have shown that long distance runners tend to have a higher percentage of slow twitch fibres (74%) in their calf muscles.
One of the main limiting factors to how fast you can run is the amount of oxygen you can get to your muscles. Oxygen is needed for your muscle cells to release energy. The maximum amount of oxygen you can take in and process is known as your VO2 max. The VO2 max of marathoners is 45% higher than an untrained person. But this advantage is largely genetic and research has shown that training only increases VO2 max by 10-20%.
What makes so many Kalenjin runners win marathons?
As the Kalenjin runners live 7000ft above see level, their genes have adapted for them to be able to live at high altitude, as oxygen levels in the atmosphere begin to fall. To overcome this, the body has to increase the amount of oxygen carrying red blood cells. This gives them an advantage when racing at lower altitudes as their heart is able to pump the same amount of oxygen but with less beats.
So are there any benefits or problems to think about if I decided to take part in a marathon?
Dehydration occurs when we lose a volume of fluid greater then 1% of our body weight. Results include decreased cardiac output and muscular strength. When running a marathon there are several things to remember:
- Make sure that you are fully hydrated before you start the race.
- Drink water at regular intervals during the race at the stations provided.
- Always replace any water you have lost after you have finished the race.
Not all runners have a problem with dehydration some of the slower runners tend to become overhydrated and are occasional put their life at risk. Both of these become even more of a problem on warm days, when the body sweats more to cool down. If you do dehydrate the body beings to suffer from hyperthermia (over heated). A large amount of blood is diverted to skin in am attempt to call it down and when doing this the muscles and brain are deprived of oxygen.
Another problem with running a marathon is that we simply don’t have enough glycogen, the first choice muscle fuel for aerobic exercise, to run 26.2 miles. The majority of people only have enough glycogen in their muscles to run 15 to 20 miles before they "hit the wall". With no glycogen left in their muscles, they have to get the energy to continue running from their body fat. But converting fat into energy is much less efficient than converting glycogen to energy – it requires more oxygen and takes twice as long, slowing a marathoner down to walking pace or even stopping them completely. To overcome this problem you need to put your body into a similar situation a few times before the race, i.e. do a couple of 20 mile runs. Endurance training leads to changes in your body’s metabolism so that you become more efficient at using stored energy as well as encouraging your muscles to store more glycogen.
Before running a race it is always best to seek medical advice and professional help when it comes to training as this will help to minimise any problems which may occur. Marathons are a great way of raising money for charities, making new friend and training towards a healthier life style.
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