For people, environmental changes can negatively impact their hydration characteristics, nutrition requirement and physical performance. As the result athletes need to be aware on how to adapt to extreme environmental conditions with proper strategies and adequate knowledge.
Effects of high-altitude on sports performance
Today’s athletes are often expected to compete in diverse and challenging environments, with high altitude and cold temperature being no exception. Some sports, like trail running, cycling and other alpine events are usually performed at more than 8,000 feet. Physical activity on high-altitude can place significant demands our cardiovascular and pulmonary system. Athletes who don’t have enough preparation for high-altitude competitions may be at a considerable mental and physical disadvantage compared to those who have successfully adapted with the challenging condition.
In a hypobaric environment (places with air pressure much lower than sea-level pressure), our body reacts by triggering some physiological responses to adapt with the lower oxygen intake at the cellular level. The air pressure is lower when we enter high-altitude environment. The lower atmospheric pressure can starve muscles from oxygen, which will cause a huge decline in VO2 max value (aerobic capacity). The respiratory center in the brain is stimulated to compensate for the lower oxygen level on the environment. As the result the depth and rate of respiration increase, to allow the brain and muscle tissues to get enough oxygen. Unfortunately, despite the higher respiratory rate, there will be little effect or even no increase on pulmonary gas exchanges, consequently, you won’t get more oxygen delivery on your tissue. Without enough atmospheric pressure to channel the oxygen into your tissue and blood, even hyperventilation won’t be effective. In addition to higher lung activity, both the resting and exercising heart rate can increase rapidly. This is a protective response needed to push enough oxygen and blood through the blood vessels and heart. Although the amount of blood pumped by our heart each minute and heart rate increase, you still won’t get extra oxygen due to lower atmospheric pressure.
Athletes who are planning to compete at higher altitudes should undergo a training plan that is designed scientifically to help them to deal with detrimental effects of hypoxia. A well-conditioned athlete may need less than three weeks to get adapted for high altitude. With enough preparation, common side effects of high altitude exposures, such as dehydration, nausea and headaches can be prevented. The preparation can also help athletes to increase the red blood cells number and expand their blood volume.
Ideally, athletes shouldn’t fly directly to an altitude of over 8000 feet, a slower ground route can allow their body to adjust to the effect of high altitude. During the acclimatization process, athletes should have enough rest to prevent the full blown effects. They are also expected to drink a lot of water, because our body may lose a good deal of water due to drier environment and faster sweat evaporation. Alcohol and caffeine are both diuretics, which can cause higher urine production, consequently both should be avoided to prevent higher fluid loss.
At high elevations, athletes must confront two options that can affect physical performance during a competition: Take a few weeks to adapt gradually or arriving within one day before the sports event. When athletes choose to spend enough time to acclimate physiologically for the hypoxic environment for a few weeks, they can reduce the bad effects of high altitude condition. However, by arriving within one day prior to the match, athletes can finish the competition before symptoms like breathing difficulty, nausea and headache can set in. Even so this strategy may not always be feasible as a good deal of planning and coordination are needed on the athletes’ part.
After two weeks preparation on higher-altitude, the VO2 max value can be 5% higher than the base value, which also means that the red blood cell mass is also five percent higher. Higher VO2 Max value equals to higher aerobic capacity, but that doesn’t necessarily translate to higher physical performance. Athletes can still have worse performance at high altitude, due to lower cardio-respiratory functions and endurance capacity. Put differently, athletes may have problems sustaining the same level of training at high-altitude environment to maintain their fitness level. Unfortunately, benefits gained from living longer at high altitude can be negated by overall lower training intensity. Many experts have shown the importance of live-high/train low strategy. The premise is that benefits gained from long-term high altitude exposure can be combined with training at lower elevations.
Due to the effectiveness of this approach, many athletes sought a more practical alternative to live-high requirement. Some companies offer hypobaric chambers or tents to circumvent the common way of getting high-altitude exposure. Those chambers can progressively lower the oxygen level by replacing with nitrogen, which simulate a hypobaric environment. Athletes can rest or sleep at these chambers regularly to get the physiological benefits without having to live in high elevation areas. To date, no controlled researches have been performed to demonstrate the benefits of hypobaric devices and its effect on overall physiological capacity and performance. In conclusion, there are proven benefits of live-high/train-low concept on the physical performance, however the cost, discomfort and time associated with this approach may not be acceptable or feasible for most athletes.