Altitude Acclimation

by: Josh Bryant

It’s 2017, and I find myself at the Tactical Strength and Conditioning Conference in Denver, Colorado. You’d think this gathering of self-proclaimed fitness aficionados would showcase the gold standard of “practice what you preach.” But oh no, the standard conditioning protocol of attendees consisted of eating fast at the International House of Pancakes!

The conference included a hands-on portion that kicked off with a simple dynamic warm-up, complete with marathon rest breaks. At least half of the attendees were sweating more gravy than a Thanksgiving feast, gasping for air like they were sprinting from the law – I’m talking an emergency room sound effect from this straightforward warm-up.

Even your run-of-the-mill, man-cave-dwelling, beer-drinking, NASCAR-watching couch potato wouldn’t wheeze like these folks. But then, like a punchline to a bad joke, someone chimes in, “Hey, don’t forget, we’re a mile above sea level!”

High Altitude

The problems presented in training, competing, warfare and surviving at high altitude are as true today as they were nearly 2,000 years ago. A quote that summarizes it well is from Tookim, a Chinese official addressing the Generalissmo Wang Fung in 35 B.C. after crossing the Greater and Lesser Headache mountains near the Korakorams: ”…men’s bodies become feverish, they lose color, and are attacked with headache and vomiting: even the asses and cattle being all in like condition”. 

The effects of high altitude on humans are substantial. Not being prepared can mean the difference between winning and losing for an athlete, and for a tactical athlete, it could be a matter of life or death.

The percentage of oxygen saturation of hemoglobin governs the content of oxygen in the blood; at 7,000 feet (2100 meter) above sea level, the saturation of oxyhemoglobin in the human body starts rapidly reducing. Though, the human body has both acute and long-term adaptations to altitude that allow for it to partly compensate for the lack of oxygen. This adaptation has a limit; that is why altitudes above 8,000 meters (26,000 ft) are known as a “death zone“, or the altitude at which human bodies are unable to acclimatize.

Climate and altitude can have detrimental consequences on the effectiveness of warfighters, in recent conflicts, in particular, Afghanistan, military personnel were asked to perform missions at thousands of feet above sea level, and research and reports have shown this could have hindrances on physical and cognitive performances of service members.

Average air temperatures are reduced 2°C (3.6°F) for every 300-m (984-ft) rise in elevation. Besides temperature changes, altitude can affect the quality and quantity of sleep and are influential factors that regulate whether individuals acclimatize well. Disturbances in sleep are related to how high the altitude and the length of exposure. Studies at very high altitudes show as high as a 50 percent reduction in total sleep time and a fivefold reduction in the REM (rapid eye movement) sleep stage. At high altitude, it is commonly reported “being awake half the night”, “not being able to sleep”, and having “frequent disturbing dreams”. Problems of sleeping can contribute to many negative performance affects. 

The US Army Research Institute of Environmental Medicine (USARIEM) have recently been studying the causes and medical effects of high-altitude exposure.  While the effects of altitude have been known for a long time, this research is helpful because it is specific to the military and it’s shown there are measurable decrements by which physical and cognitive performance can be evaluated as the environment increases in elevation. Bottom line is, for humans, as altitude increases, performance decreases.  This is, in a large part, due to the reduced oxygen and air pressure that decreases the availability of oxygen resulting in hypoxia which is an inadequate oxygenation of the blood.

The USARIEM research has shown, “At 4,000 ft. above sea level you first start seeing a lack of physical performance. At 8,000 ft. is usually the altitude at which cognitive performance is affected. And we’ve found that 10,000 ft. is the threshold where judgment starts to become impaired,” said army research physiologist, Stephen Muza. 

8,000 feet above sea level is were altitude sicknesses set in, particularly Acute Mountain Sickness (AMS) symptoms which include nausea, headache, dizziness and shortness of breath.  AMS is very common but recovery is fast with descent and rest; nonetheless, this can be debilitating if you are not prepared.

There are several ways tactical athlete/athletes can prepare for high-altitude environments prior to deployment with the most obvious being to start training at a higher altitude. High-altitude training facilities are located at some military installations in the U.S. including the following locations Fort Carson, Colo., the Marine Mountain Warfare Training Center, Calif., and at Hawthorne Army Proving Ground, Nev.

Besides high altitude training prior to deployment, tactical athletes benefit from living a healthy lifestyle, specifically not smoking and eating a well-balanced diet. “Since the carbon dioxide in cigarettes decreases the amount of oxygen the hemoglobin in your blood can carry, you’re getting even less oxygen and putting yourself at a greater risk at a higher altitude,” says Muza. This is of grave importance when involved in high-altitude warfare and training. 

Performance can be affected in the following ways at altitude:

• Decreased long, slow endurance aerobic performance
• Reduced ability of oxygen to reach the body’s tissues
• Rate of breathing and ventilator volume increases to assist in getting more oxygen to the lungs
• Increased heart rate
• All the following decrease: maximal oxygen consumption, cardiac output, stroke volume, maximum heart rate thus reducing work capacity
• Increased breathing and urination
• Increased hemoglobin and hematocrit in the blood, improving the ability to carry oxygen
• Increased metabolism with decreased appetite (weight loss)
• Decreased sleep/fatigue
• Digestive disorders
• Agitation/vertigo
• Headaches
• Nausea/vomiting 

To minimize the negative effects of altitude, the you need to acclimatize to the elevation in you will be training, competing or performing a mission.  For moderate elevations, this can be as short as four days, the typical strategy used by armed forces is to arrive at a site a week prior to the scheduled mission or training is taking place.  Keep in mind, if troops have remained at a 5,000-foot altitude but their mission is at 10,000 feet they will need to reacclimatize.  Proper acclimatization provides a huge advantage for the tactical athlete.

Become a certified Tactical Strength and Conditioning Coach with Josh’s Course through ISSA HERE.