Measuring specific, exercise-related responses can help physicians determine who may be more at risk for severe high altitude illness (SHAI), according to a study conducted by researchers in France. The researchers also found that taking acetazolamide (ACZ), a drug frequently prescribed to prevent altitude illness, can reduce some of the risk factors associated with SHAI.

The findings were published online ahead of the print edition of the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.

The three exercise-related factors identified by the researchers include oxygen desaturation at exercise (Sae), hypoxic cardiac response at exercise (HCRe) and hypoxic ventilatory response at exercise (HVRe). Sae measures the amount of oxygen that is in the blood during exercise; HCRe measures the heart’s response to exercise in a hypoxic, or low oxygen, setting, and HVRe refers to respiratory changes (notably rapid breathing) that occur during exercise in a hypoxic setting.
The researchers measured these parameters in controlled, hypoxic conditions in a lab setting that mimicked high-altitude conditions.

“These results suggest that HCRe, HVRe and substantial decreases in Sae are independent risk factors of SHAI, and that decreases in Sae and HVRe can be used to accurately predict the risk of developing SHAI,” said Jean-Paul Richalet, MD, PhD, a professor of physiology at Université Paris 13.

“To date, this is the largest epidemiological study of subjects exposed to high altitude-related illness, who were previously evaluated for their responses to hypoxia,” he added.

The researchers collected data from 1,326 men and women who were seen prior to high-altitude excursions, which included at least 3 days above 4,000 meters with overnight sleeping above 3,500 meters. Study participants were asked to complete a questionnaire, providing information about their personal and family medical history, usual physical and mountaineering activity and other factors.

Next, study participants went through a routine hypoxic exercise test, which consisted of four, four-minute phases: rest at normal oxygen levels; rest at hypoxic levels; exercise in hypoxia; and exercise in normal levels of oxygen. During the exercise test, the researchers measured heart rate, breathing and blood oxygen levels.

Following their excursions, study participants were asked to complete a questionnaire to determine if they had experienced any symptoms of high altitude pulmonary edema (HAPE), or swelling of the lung tissue; high altitude cerebral edema (HACE), which refers to swelling of the brain tissue; or severe acute mountain sickness (AMS), which can include a variety of symptoms, including headache, nausea, fatigue and dizziness. Participants were also asked to indicate if they had used ACZ.

Among the 1,326 questionnaire respondents, 318 reported that they had experienced a severe altitude illness during their high-altitude excursion, including 105 who used ACZ and 213 who did not.

Using these results, the researchers were able to identify which factors, reported both before and during the excursions, were associated with SHAI. They were also able to determine the effect of ACZ on the development of SHAI.

“We found that among those who did not use ACZ, factors including young age, female gender, history of migraine, regular physical activity, previous history of severe altitude illness, rapid ascent, HCRe, substantial changes in Sae and HVRe were significantly associated with SHAI,” Dr. Richalet said. “Geographically, the area of Ladakh, India, was associated with a higher risk of SHAI among non-ACZ users.”

In those respondents who used ACZ preventively, young age, female gender, history of migraine, regular physical activity, HCRe, substantial changes in Sae and the Alps were no longer significantly associated with SHAI, Dr. Richalet noted, but Ladakh retained borderline significance. A history of SHAI, rapid ascent and HVRe were still associated with SHAI in those who used ACZ, but the associations were not as strong as those noted in non-ACZ users.

They also found that preventive use of ACZ resulted in a 44 percent reduction in the risk of developing SHAI.

“Although it was not double-blinded and placebo-controlled, this study confirms in a large number of subjects the efficacy of the preventive use of ACZ in high-altitude-related illness,” Dr. Richalet said. “These results indicate that preventive use of ACZ may reduce the risk of SHAI in susceptible subjects to the same level as that of non-susceptible subjects.”

The study also linked frequent physical activity to an increased risk of SHAI, a result which Dr. Richalet said supports the common belief among mountaineering experts that increasing the body’s ability to absorb oxygen during exercise is not a predictor of success in high-altitude expeditions.

“Of course, that does not mean that those who visit high altitudes should stop training before an expedition, but they should realize that intense aerobic training is not a protective factor against altitude-related disorders,” he said.

The study is the first to suggest an independent association between the geographical location of ascent and SHAI.

“When adjusted for all other risk factors, especially rate of ascent, one location – Ladakh – remained associated with a higher risk of SHAI in both ACZ and non-ACZ users,” Dr. Richalet said. “No clear explanation, linked to the climate or the difficulty of the terrain, is available, although many informal reports mention the higher risk of this location.”

Dr. Richalet said that although previous episodes of SHAI are still the best predictor of new episodes, results of the study support the use of hypoxic exercise testing, especially in individuals who are planning their first high-altitude excursions.

“Ideally, testing should be aimed both at subjects with no previous experience of high altitude, who therefore lack information about potential risk factors, and those who have experienced severe symptoms in the past, in order to determine if those episodes of SHAI were due to physiological characteristics,” he said. “And of course, during a visit to high altitude regions, it must be emphasized that the best way to avoid severe symptoms is to ascend slowly – less than 400m of altitude difference between two consecutive nights above 3000 meters during the acclimatization period.”

AB Managing Editor: By Michael Popke —

A second man has died following an underwater training accident at a public pool on Staten Island. The New York Daily News reports that 21-year-old off-duty lifeguard Jonathan Proce died Sunday at New York Presbyterian Hospital following an exercise at Lyons Pool last Wednesday in which he and his friend, Bohdan Vitenko, also 21, were practicing underwater breath-holding.

The two were found unconscious and in cardiac arrest in three feet of water at the bottom of the pool; Vitenko died later that day. Two lifeguards have been pulled from their duties after failing to notice Proce and Vitenko, according to The New York Post. Approximately 20 other swimmers were in the pool at the at the time, the paper reports.

Proce was bound for the U.S. Air Force, while Vitenko had dreams of becoming a Navy SEAL. They were regulars at the pool, reportedly participating in a grueling workout routine that included swimming and underwater sit-ups. It is not clear if the men were following an official training program or had developed their own workouts. Either way, the military advises against certain breath-holding exercises or swimming underwater at length to avoid “shallow water blackout,” which can lead to drowning.

According to ShallowWaterBlackoutPrevention.org — an awareness and education site — the condition occurs because of low carbon dioxide and low oxygen (which triggers unconsciousness). Hyperventilation done before breath-holding lowers carbon dioxide abnormally, allowing individuals to hold their breath longer. But the lower carbon dioxide levels rob the body of its built-in mechanism to tell the breath-holder to breathe before going unconscious and taking water into the lungs.

Additionally, “because of the hypoxia, one feels euphoric and empowered to continue breath-holding,” the site states. Unlike regular drowning, where six to eight minutes can elapse before brain damage and death, brain damage and death caused by shallow water blackout can occur within two and a half minutes. More information about shallow water blackout can be found on the Aquatic Safety Research Group’s website.

In 2008, the National Swimming Pool Foundation warned that “anyone who practices competitive, repetitive underwater breath-holding is at risk for shallow water blackout. Once submerged underwater, the swimmer may be hidden from the view of lifeguards by surface glare and ripples/waves on the surface. A series of events is then triggered, including the inhalation of water, possible convulsions and ultimately cardiac arrest and death.”

Dr. Gary Wadler, M.D., the chairman of WADA’s Prohibited List and Methods Subcommittee, says: “There’s tremendous individual variability that makes it hard to predict who will benefit,” .
“In a highly controlled, hospital-level environment, the equipment probably isn’t dangerous,” he says. More worrisome to Wadler are the muscle-heads who will try to cut costs by using homemade setups.
“But if you’re using inferior equipment, there’s a potential to get a severely low intake of oxygen that could result in irreparable damage to the brain.” The lesson here: use the right gear, or risk brain damage or even death.

Here’s a way to get an advantage over the other guys…legally.
Australia Men’s Health Magazine

Acute Mountain sickness (AMS) is the term given to a number of symptoms that occur after rapid ascent to high altitude.   Severe forms may be life threatening because of pulmonary or cerebral oedema.  Mild forms of this illness can affect up to 50% of population traveling to altitudes above 12,000 - 14,000 ft.

Symptoms of headache, malaise, and decreased appetite are fairly common amongst individuals traveling to altitudes greater Than 8,000 ft, but these can occur event at lower altitudes.

The mild forms of mountain sickness can usually be treated with rest, hydration, analgesics (eg. ibuprofen), and alcohol avoidance. If you are already experiencing these symptoms do not go to higher altitudes.

Slow progressive step-acclimatisation can help minimising severity of AMS.
Individuals who have already experienced an episode of mountain sickness are at risk for future trips and should seek medical advice.

Severe forms are characterized by severe shortness of breath, cough, severe headache, confusion, or hallucinations. This may progress to coma and death. This is a medical emergency. Immediate descent to lower altitude, administration of oxygen, and medical attention are required.

A very effective method that helps  minimising the severity of mountain sickness is pre-acclimation using
hypoxicators for simulated altitude training.

The aim of the present study was to evaluate the efficacy of
intermittent hypoxic training (IHT) with 95 % of lactate threshold
workload (WRLT) on aerobic capacity and endurance performance
in well-trained cyclists. Twenty male elite cyclists,
randomly divided into a hypoxia (H) group (n=10; age 22 ±
2.7years; VO2max 67.8 ± 2.5 ml·kg-1·min-1; body height (BH)
1.78 ± 0.05 m; body mass (BM) 66.7 ± 5.4kg; fat free mass
(FFM) 59.3 ± 5.1kg; fat content (FAT%) 11.3 ± 2.1%), and a
control (C) group (n = 10; age 23.5 ± 3.5years; VO2max 67.7 ±
2.0 ml·kg-1·min-1; BH 1.79 ± 3.2 m; BM 69.2 ± 5.5 kg; FFM
63.6 ± 4.8 kg; FAT% 7.9 ± 1.94 %) took part in the research
project. The training program used during the experiment was
the same for the both groups. For three weeks, the subjects in H
group performed 3 training sessions per week in normobaric
hypoxia environment (IHT - O2 = 15.2%). During the elemental
core of the IHT session, the intensity was set at 95% WRLT for
30-min in 1st microcycle, 35-min in 2nd microcycle and 40-min
in 3rd microcycle. The same training procedure was provided in
C group, yet the intensity of the main sessions were set at 100%
WRLT in the normoxia environment. The results indicate a significant
(p < 0.05) increase in VO2max,VO2LT, WRmax, WRLT and
change in lactate concentration (ΔLA) during incremental test in
H group. Also a significant (p < 0.05) decrease in time of the
time trial was seen, associated with a significant increase (p <
0.05) in average generated power (Pavg) and average speed (Vavg)
during the time trial. The intermittent hypoxic training (IHT)
applied in this research did not significantly affect the hematological
variables considered: number of erythrocytes (RBC),
hemoglobin concentration (HGB) and haematocrit value (HCT).
Significant blood value increases (p < 0.05) were only observed
in MCV in H group. This data suggests that intermittent hypoxic
training at lactate threshold intensity and medium duration (30-
40min) is an effective training means for improving aerobic
capacity and endurance performance at sea level.
http://www.jssm.org/vol10/n1/24/v10n1-24abst.php

Friday January 07 2011

FIONNUALA Britton has turned down an invitation to compete in tomorrow’s Great Edinburgh Cross-Country championships in favour of travelling to South Africa this week for a month’s high-altitude training.

And she is joined there by Sligo’s Mary Cullen, another Irish athlete who knows only too well the frustration of finishing fourth in the European Cross-Countries.

While Britton was heartbroken to be just outside the medals in the Algarve before Christmas, Cullen was equally frustrated by having to sit out that event after breaking her collarbone in a fall from a bicycle.

Cullen is back training now and targeting a return in time for the European Indoors in Paris in March, a competition at which she won bronze last time out.

Both women will spend most of this month in a training camp at Potchefstroom, which also includes Ireland’s European 100m hurdles silver medallist Derval O’Rourke.

National inter-county champion Joe Sweeney (DSD) and Clonliffe’s Mark Kennelly will dominate Irish interest in Edinburgh after being selected on the European team in the inaugural men’s ‘international’ 8km race.

But recent European U-23 team gold medallist Mick Mulhare, his brother Dan, Mark Christie and Stephen Scullion are all racing in the earlier men’s 4km. The ‘international’ pits Britain’s double European track champion Mo Farah against his cross-country nemesis and European captain Sergey Lebid, while America will be skippered by Galen Rupp.

Lebid and Farah have had some cracking cross-country battles in recent years, including Edinburgh in 2007 and the 2008 European Cross Countries, both won by the Ukranian.

The men’s 4km features a host of Olympic and World medallists, including big-name Kenyans Eliud Kipchoge, Asbel Kiprop and Brimin Kipruto.

Kiprop is the reigning Olympic 1,500m champion, while Kipruto holds the same title in steeplechase.

The women’s race also has a star-studded field, which includes Kenya’s current world 5,000m and 10,000m champions Vivian Cheruiyot and Linet Masai as well as two-time world junior cross-country champion Genzebe Dibaba of Ethiopia and Portugal’s European champion Jessica Augusto.

Edinburgh Cross-Country

Live, tomorrow, BBC 1, 1.30

- Cliona Foley

FULL STORY

GO2Altitude has a publication section which includes articles on altitude training from various magazines.

Fitness & Training

Introduction

The Australian Sports Commission or the Australian Institute of Sport does not provide personal fitness or training programs. For an individually tailored program contact a coach or fitness centre in your area. For contact details of sporting organisations that may be able to direct you to the closest coach within Australia, try our directories page . Before undertaking any training or fitness program you should first check with your physician, and also verify with a professional the appropriateness of the program for you.

http://www.ausport.gov.au/information/finding_sport_information/topic/fitness

http://www.researchgate.net/publication/7474551_VO2_responses_to_intermittent_swimming_sets_at_velocity_associated_with_VO2max

High Performance Equine Hypoxicator

Until recently, training horses at “altitude” in the same way as for humans was impractical.

However, what was once impractical is now a real option for race horse trainers with the advent of Intermittent Hypoxic Training (IHT) or simulated high altitude training.

Simulated high altitude training can vastly improve athletic performance by deliberately inducing hypoxia with the animals body producing more red blood cells, which in turn results in increased oxygen delivery to the tissues such as the heart, lungs and skeletal muscle.

There is no evidence that IHT will enhance the performance of the animal beyond its own genetic potential. But there is evidence that IHT does have a therapeutic role in minimising muscle damage associated with strenuous exercise.

Other applications of IHT include acclimatization of horses for air travel, enhance effects on fertility, and assists with the management of lung disease associated with Exercise Induced Pulmonary Haemorrhage in horses.

Please email us at vetandpetproducts@bigpond.com for sales price or other information enquiries. NB: The price for this product is not listed on the webpage, please contact us for further details.

http://www.vetandpetproducts.com/catalogue/c18/c280/c281/p1468

By Brendan Gallagher

With the next year’s Tour de France spending a significant time 2000 metres above sea level next year Dave Brailsford, the team principal at Team Sky, has asked his sports scientist to overhaul his their training schedule for riding at such altitude.

A failure to ride competitively on the very highest reaches of this year’s mountain stages was quickly identified as the root cause for Bradley Wiggins being unable to get on terms with the main yellow jersey contenders and was already being looked into by Brailsford and his team.

Although Sky trained on all of the highest climbs in this year’s Tour, unlike most teams they did not organise long camps at altitude before the three-week race, but it is something they are seriously considering for 2011.

http://www.telegraph.co.uk/sport/othersports/cycling/8075275/Tour-de-France-2011-Team-Sky-preparing-for-altitude-training-ahead-of-Alpine-endeavours.html