Altitude Training – Why, When And How To Get High (Part 1)
[Article by Tait Hearps of Sweat Elite]
The effects of training at altitude on athletic performance have undergone much scrutiny in recent decades. Many athletes who have dominated the domain of long distance running have spent their lives living and training at altitude – notably the East Africans in Kenya, Ethiopia and Uganda who almost exclusively come from high elevations. And since the 1968 Olympic Games in Mexico City, which took place at 2200 metres above sea level, the vast majority of medallists at major championships have either lived or trained at altitude. Here we will look at the effects of altitude training on the body, why athletes incorporate it into their training regimes, and how you should go about trying it out for yourself.
Nowadays, altitude training is a component of virtually all elite running programs. Many elites are flocking to elevated hubs such as Flagstaff, Boulder, and lesser known spots in Kenya, Ethiopia and Mexico. But what is it about running at altitude that can give such a boost to athletic performance?
The answer to this question is multi-faceted, complex and highly variable between runners, but there are some physiological mechanisms that are inextricably linked to the endurance benefit that altitude training can provide.
Firstly, we must establish what qualifies as “altitude training”. It is generally accepted that between 1800m (~6,000 feet) and 3000m (~10,000 feet) is most beneficial. However, research to elucidate the optimal parameters under which altitude training impacts performance – the altitude that generates the most significant physiological changes – is still ongoing. Many professionals agree that around 8,000 ft is the ideal elevation for training, however due to the variability of how athletes react to altitude, it is difficult to conclusively determine a sweet spot.
How does training at altitude differ to training at sea level? The key difference is the air pressure. As you ascend into the sky, air pressure diminishes. This means that in a given volume of air there are fewer particles of oxygen. Each lungful that you inhale brings with it fewer and fewer particles of oxygen as you climb up the side of a mountain. People commonly believe that there is less oxygen at altitude however the air is the same mixture as at sea level – nitrogen, oxygen, carbon dioxide and other components are all present in the same proportions – only the particles are more dispersed. For example, barometric pressure decreases from 760mmHg at sea level to 604mmHg at 2000m, meaning that each litre of air has only 80% of the oxygen that a litre at sea level does. Lower pressure, less oxygen, so what?
Low pressure and less oxygen per breath means that less oxygen enters the bloodstream, which results in hypoxia (low blood oxygen concentration). This hypoxic change triggers the release of EPO from the kidneys. EPO, sound familiar? Yes, altitude training is essentially a natural form of doping. The reason EPO is used as a performance enhancer by athletes is that it signals for the bone marrow to upregulate haematopoiesis – generating more red blood cells (erythrocytes). This has huge benefits to athletic performance as it is the erythrocytes that carry oxygen on the haemoglobin they contain.
EPO peaks between 24-48 hours after arriving at altitude. Studies with elite athletes show that haemoglobin levels can increase by around one percent per week at altitude. This is an adaptation to enhance oxygen carrying capacity, compensating for the lower levels available at altitude, and translates to a benefit in aerobic performance when returning to the oxygen dense air at sea level. Evidence suggests that non-elite athletes – who have lower initial haemoglobin levels – stand to benefit from an even more potent boost than the elites.
Not only does the lower oxygen partial pressure result in hypoxia and haematopoiesis, it also can have greatly beneficial psychological effects. The shortage of oxygen entering the blood means that respiratory centres in the brain are stimulated. You’ll be panting whilst running at what would be an easy pace back at sea level. Hypoxia results in anaerobic metabolites being generated, muscles feel heavier and sessions have a higher perceived level of exertion, even when the pace is decreased. This means that you can push harder and become more accustomed to severe discomfort with less stress on joints and muscles compared to that which running faster or farther at sea level would cause.
This sounds great, right? I mean, aside from the discomfort and panting, a natural boost in performance is a pretty big drawcard. So now, how do you go about trying out altitude training for yourself?
Continue reading in Part 2.
