Exercise and Altitude
Depending on if you are traveling to Lake Tahoe to ski, Colorado to mountain climb, Ashville to hike, or even Vermont for business, you will need to consider that you will be facing a different altitude than the environment that you reside in. It is important to be mindful when experiencing these new heights and pressures, as it can take a toll on you physiologically. One’s body has to adjust to the new surroundings in order to “survive” through this adaptation. It is especially vital to be aware of these changes when choosing to participate in exercise of any form while in the new altitude level.
Altitude is a distance measurement, generally in the upward direction, from one point to another. Commonly altitude is referred to the height above sea level of a location. High altitude is sometimes defined as 2,400 meters (8,000 ft.) above seal level. Medically high altitude is defined as: High Altitude: 1500 – 3500 m (5000 – 11500 ft), Very High Altitude: 3500 – 5500 m (11500 – 18000 ft), and Extreme Altitude: above 5500 m . Annually, more than 100 million tourists are attracted by the mountainous areas around the world. On the one hand, leisure time activities at altitude may well contribute to the well-established beneficial effects of exercise; on the other hand, these activities are also associated with a relatively high risk of death . It is important to be aware of these risks when encountering high altitude to be able to adjust your activity and/or exercise to a safe level.
To avoid any complications when you are experiencing a change in altitude, it is recommended that one should let the body acclimatize. Acclimatization is the process of the body adjusting to the decreased availability of oxygen at high altitudes. It is a slow process, taking place over a period of days to weeks . Some people acclimatize quickly, and can ascend rapidly; others acclimatize slowly and have trouble staying well even on a slow ascent. Certain normal physiologic changes occur in every person who goes to altitude, such as, hyperventilation (breathing faster, deeper, or both), shortness of breath during exertion, changed breathing pattern at night, awakening frequently at night, increased urination . As one ascends through the atmosphere, barometric pressure decreases (though the air still contains 21% oxygen) and thus every breath contains fewer and fewer molecules of oxygen. Therefore, one must work harder to obtain oxygen, by breathing deeper and faster, more and more as the altitude is increasing. This is particularly noticeable with exertion, such as walking uphill . When exercising or doing any activity that exerts the body, shortness in breath is not uncommon. However, the breath should regulate after quick rest under normal circumstances. It is critical that acclimatization takes place or one can be faced with many health related issues.
If you are not careful in letting one’s body acclimatize, one can face serious illness. The lack of oxygen above 2,400 meters (8,000 ft) can cause serious illnesses such as altitude sickness (or acute mountain sickness, (AMS)), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE) . Symptoms range from headache, fatigue or weakness, loss of appetite, dizziness or lightheadedness, and difficulty sleeping all the way to extreme fatigue, breathlessness at rest, fast while shallow breathing, cough and/or gurgling, chest tightness, blue or grey fingernails, and drowsiness . Sudden cardiac death (SCD) is even linked with high altitude activities . Various medications can cause respiratory depression, which can also contribute to problems at altitude. Some examples of these medications are alcohol, narcotic pain medication, and sleeping pills. These medications should be avoided if possible and never should be used when experiencing symptoms of altitude illness.
By assessing the performance of elite athletes, who are performing at an “all-out” effort in precisely timed events for which they are trained, it is determined that: a) the magnitude of sub-maximal exercise impairment is proportional to both the elevation and exercise duration at a given altitude; and b) sub-maximal exercise performance at altitude can improve with continued exposure without an increase in VO2max . Muscle strength, maximal muscle power, and anaerobic performance at altitude are not affected as long as muscle mass is maintained. In addition, performance is not impaired in athletic activities that have a minimal aerobic component and can be performed at high velocity (e.g., sprints) .
The key to avoiding AMS and other altitude illness is a gradual ascent that gives your body time to acclimatize . People acclimatize at different rates, so no absolute statements are possible for exact exercise prescription in relation to time encountering altitude. However, with knowledge of the possible health risks faced in altitude, one can be precautionary when beginning an exercise program. Once reaching acclimatization, normal exercise is permitted as long as there are no presenting symptoms suggesting otherwise. Also, it is important to know when to rest, go down in altitude, and continue to hydrate and eat adequately to avoid any complications.
Don’t let this information be discouraging to partake in any physical activity that you wish to do in altitude, however, let this material serve as knowledge to be more educated on exercise in altitude, therefore, preventing anything negative from happening.
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