Three weeks post-altitude is the longest time that researchers have looked, so we've made an estimate based on our understanding of the physiology. If we assume the increase in mass of red blood cells is the main factor accounting for increased performance and that production of red cells returns to normal soon after return from altitude, the effect should last the lifetime of the cells.
The lifetime is about four months in the average adult, but apparently only months in athletes training hard reviewed by Szygula, , but he does not cite accessible references. So we expect the benefits to begin to wane by the end of the second month after altitude exposure, and to have disappeared completely after three or four months.
Studies in which athletes have received infusions of extra red cells provide indirect evidence for and against this estimate.
In one study, the infusions produced an enhancement of endurance performance that had returned to baseline after 16 weeks, although maximum oxygen uptake remained high Buick et al. In another study, published only as an abstract, maximum oxygen uptake and performance had returned to normal after four weeks Goforth et al. When the effect of altitude exposure has waned, further exposure should stimulate production of red blood cells again and restore performance.
Whether the effect is re-established more quickly or augmented is not known. Living up a mountain and coming down to train is just one of six or seven ways to get the effect of altitude exposure while maintaining training intensity. We summarize here the various strategies. Use a Mountain and Valley. Living at altitude and descending to do high-intensity training three or four days a week is the literal way to live high and train low.
The main problem is a shortage of suitable mountains, so for most athletes this option means the expense and stress of international travel and of living away from home for up to a month. Loss of heat acclimatization may also be a problem if the high and low training venues are too cool. Stay High and Train Hard with Oxygen. If your mountain does not offer the possibility of training low, you may be able to do your hard training on a sport-specific ergometer while you breathe oxygen-enriched air through a face mask.
Although this option gives you a wider choice of mountains, you may still have problems with international travel and time away from home, and it doesn't suit all sports e.
There has also been little research on its effectiveness. Live in a Nitrogen House. The Finns have pioneered use of dwellings that can be flushed with air diluted with nitrogen Rusko, A nitrogen house can be sited almost anywhere as a fixed or mobile facility and is probably the most cost-effective way to deal with teams of athletes.
But athletes still have to suffer a dormitory lifestyle away from home. Rest and Sleep in a Nitrogen Tent. A mini version of a nitrogen house, in the form of a tent, has recently appeared on the market.
See the website. It simulates altitudes of up to m ft and can be modified to simulate up to m 14, ft. The tent is set up on a bed or on the floor. The advantages are substantial: it is truly portable; it can be used with little or no disruption of family life, study, or work; and it is easily the best way to establish the altitude and program of exposure that suits the individual. Breathe Through a Nitrogen Mask Intermittently. We have heard that Russian researchers are investigating the effects of breathing oxygen-depleted air through a face mask for an hour or two, several times a day.
Such treatments can increase the production of erythropoietin Knaupp et al. Research is needed to determine the effectiveness of the treatment relative to longer exposures in nitrogen houses or tents. Live in a Large Barometric Chamber. Large steel chambers that can be evacuated to simulate high-altitude flying may be available at a national air-force establishment. This method of achieving altitude exposure has not been used for live-high train-low research yet, but there is little doubt that it would enhance performance.
There are no specific advantages, and there are several disadvantages: high running costs, national travel to the chamber, daily travel between the chamber and training venue, a month's absence from home and work, and a severely cramped dormitory lifestyle with little privacy. Rest and Sleep in a Personal Barometric Chamber. This device consists of a rigid cylinder little bigger than a person, with windows at each end and a vacuum pump attached. It has been available commercially for several years.
Like the nitrogen tent, it can be used at home, but it's too cramped to accommodate a partner. It's also twice the price of a nitrogen tent, less easy to use, and less transportable. It may also be more noisy and uncomfortably warm. Use Erythropoietin or Blood Doping. There is little doubt that some top athletes have been taking injections of erythropoietin to get the increase in red blood-cell mass that normally accompanies altitude exposure.
Intravenous infusion of extra red cells blood doping has a similar effect Sawka et al. With excessive use, both strategies are dangerous: the blood becomes so thick that there is a risk of sudden death from blood clotting. So for reasons of fair play and health, their use is banned by the International Olympic Committee. Ironically, altitude exposure may be more effective anyway, if the increased buffering capacity of muscles that seems to occur with altitude exposure contributes to the enhancement of performance.
In his review of this article, Allan Hahn questioned whether altitude training could be more effective. Our reply: if erythropoietin injections and blood doping are more effective, it may be only because they increase the red-cell mass to a dangerously high level.
We predict an athlete will get more performance enhancement by using altitude exposure to reach the permissible limit of red cells in the blood than by using erythropoietin or blood doping to reach the same limit. There are two good reasons for banning a practice that enhances performance: either it causes illness or injury, or it gives the athlete a technological advantage that is too expensive or too new for most other competitors to use.
Let's see whether the different methods of altitude exposure should be banned. Living on a mountain is obviously ethically acceptable--in fact, it probably seems romantic to the public, who ultimately determine the ethical stance of sports bodies. Frequent trips down to the valley are also unlikely to be considered unsporting. But aside from the temporary altitude sickness, is altitude exposure damaging to health? In a small proportion of the population, continuous exposure to altitude leads to accumulation of fluid edema in the lungs and brain, which can be fatal Krasney, In another small proportion, excessive production of red blood cells increases the risk of sudden death through blood clotting or a heart attack Coote, The average athlete who spends a few weeks at a moderate altitude will not have these problems.
Altitude chambers, nitrogen houses and nitrogen tents would be dangerous if the simulated altitude was high enough and long enough to raise the thickness of blood to an unsafe level. An athlete using a personal altitude chamber or tent might well overdo it, but so far no one has made a public case for banning these devices on the grounds of health or safety.
It also seems unlikely they will be banned as an expensive innovation, because they are no more expensive than the high-tech equipment used in training or performance by many Olympic athletes. If they aren't unethical, are they unsporting? A government-sponsored altitude facility is reminiscent of the Eastern Bloc's approach to national Olympic glory.
Somehow it's less objectionable if the individual athlete pursues this avenue of performance enhancement via a personal altitude chamber or tent. Still, it will be a sad day when all endurance athletes have to spend weeks of their lives in such apparatus to keep up with other competitors. Can they be banned? No, because you can't ban normal altitude training, so it's unfair to ban a safe practice that makes it easier or cheaper for athletes to achieve the same effect.
The practices are safe only if the blood doesn't get too thick. Partly for this reason, some sports have set limits either on the proportion of blood cells the hematocrit in a blood sample Martin et al. Research currently in progress will determine which of these tests is more effective, where to set a fair limit, and how to deal with athletes' attempts to cheat the test.
The resulting blood test may be a simple and highly effective way to keep use of real and simulated altitude exposure within safe limits. Table 1: Studies of living and training high. Saltin, c. VO2max: maximum oxygen consumption. Performance change is relative to control group. Data shown are from the review by Hahn Table 2: Studies of living high and training low.
Adams, W. Effects of equivalent sea level and altitude training on V02max and running performance. Journal of Applied Physiology, 39, Baumann, I. NSA Round Table: high altitude training.
New Studies in Athletics, 9 2 , Bovard, R. If athletes are not sufficiently prepared for a training camp and are slightly anemic, they can come back crippled physiologically. Another issue with elevation is that you must alter hydration and diet, as the resources needed for the same training load are higher, especially if you increase the training to challenge the body.
Additionally, due to the strain on the body, some athletes risk immunosuppression and can get sick from the combination of training hard and living at altitude. Athletes sometimes use a training camp to help with peaking, while others try to develop a base so they can train harder in their next preparation phase. Altitude is about elevation above sea level, and most coastal cities are considered near zero in elevation. For every meters above sea level, small changes in the human physiology can occur, but the magic usually starts at 1,, meters up, and 2,, is a sweet spot for ideal conditioning.
In fact, most large cities are closer to sea level than at elevation, and looking at the coasts, you can see that the human population loves the ocean. Peru is home to the highest city in the world, but China has the majority of the top positions in elevation.
Figure 2. The relationship between hours of altitude training and hemoglobin mass is a simple one. As athletes spend more time at altitude, their oxygen-carrying capacity increases. Modified from Gore et al. Athletes can sleep in altitude and even live in houses that simulate hypoxic conditions. Of course, some athletes still practice the old-school LHTH or Live High Train High approach entailing relocation for a short period of time if necessary to induce physical changes.
Progressive coaches and athletes use other combinations like Live High and Train Low and High, or Live High and Train Low in the Heat, but we do not know much about how well those approaches truly work. The most important takeaway from this article is that everyone is different, but not that different. My biggest complaint in sports is that we treat everyone like either a clone or the other side of the extreme—we prepare athletes with too much personalization with the expectation that those small differences will make a real change.
I do believe that the little things can add up the spectacular, but marginal gains only work when the major priorities are in place. Instead of waiting to talk about athletes who should not go to altitude training camps, I should have placed the discussion first, for good reason.
Athletes who are iron-deficient—a significant population, as a matter of fact—should stay home. The variability in results with training camps is due to the fact some athletes actually come home impaired further in regard to red blood cell production, and could come back anemic. An easy way to prevent anemia is to periodically screen the blood and focus on iron stores, not hemoglobin or other indices. As athletes train, blood parameters like plasma volume increase, so false positives of anemia can occur.
Detailed training records and simple blood tests may be enough to screen properly, but if you want to know whether athletes can actually transport more oxygen precisely, they need to do lab testing.
Figure 3. Athletes will respond to altitude differently based on their DNA. Some athletes respond very well, while others actually respond negatively and may encounter symptoms of fatigue or illness. Stress is stress, and training at elevation could put an athlete who is fragile out of commission. While some athletes get a great endorphin response, others comment that they lose that response at altitude.
Most of the research on altitude has trouble blinding an athlete from knowing whether they are elevated or not, so placebos are always going to be an issue with the research. On the other hand, endurance athletes benefit less than recreational level athletes because they tend to be better prepared and near their ceiling, so team sport athletes might be a good fit if the organizers are smart and have done their homework.
Others seem to have dramatic changes. However, as usual, both extreme responses to altitude are outliers. You can read more about anemia here. We recommend proper blood testing to determine whether or not you have anemia. An iron supplement is a good idea to prevent the fall into anemia — which can take months to recover from as well as your performance!
Perhaps the biggest challenge to athletes at altitude is just acclimatizing, or getting used to the relative lack of oxygen and dry air. Lack of appetite is common at altitude; the same nutrition rules apply here as well as in the flatlands.
However, even the most diligent athletes will still feel the effects of altitude; the following can take the last remaining edge off. Homeopathic Cocoa has been studied on Mount Everest and significantly increased oxygen saturation in climbers who took it. Gingko biloba is a popular botanical medicine. Taken before ascending to altitude, it can lessen the severity of altitude sickness symptoms. Rhodiola is an extremely helpful botanical medicine for all athletes.
It aids performance at altitude by helping the body to adapt in stressful conditions through a number of mechanisms. West, J. Prediction of barometric pressures at high altitudes with the use of model atmosphere.
J Appl Physiol. Szygula, Z. Erythrocytic system under the influence of physical exercise and training. Sports Medicine. Shackelton MF, et al. Everest Base Camp. Complementary Health Practice Review, Vol. Gertsch JH, et al. Ginkgo biloba for the prevention of severe acute mountain sickness AMS starting one day before rapid ascent. High Alt Med Biol. EGb in control of acute mountain sickness and vascular reactivity to cold exposure. Aviat Space Environ Med. DeBock K et al.
Even within a single year, top athletes use repeated altitude camps to keep building on the previous camp. The review includes training details from several Olympic champions: a swimmer who did 34 camps totaling weeks over eight years; a cross-country skier who spent more than 60 days a year at altitude; a racewalker who spent 45 to 60 days a year.
This heavy use leads the authors to a somewhat provocative suggestion. But many of the studies that find non-responders are one-off studies using non-elite athletes who have never been to altitude before. How long before your big race should you return from altitude? Every coach has different answers. The most common advice is that you should either race within the first two or three days at sea level, or else wait two or three weeks.
All of these factors may have wide individual variation, making it very difficult to pinpoint the right timing. Training data from the Olympic champions was all over the map, with both the skier and swimmer sometimes coming down 7 or 8 days before major championships, right in the middle of the supposedly bad window.
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