Altitude has this great mystique and allure in the world of distance running. The mystique has grown over the years. It started when we saw the impact altitude had on performance at the Mexico City Olympics. But it really took off when the East African onslaught of records occured, where we saw the impact training at altitude had on performance.

For many, altitude is the answer. They swear by it and do everything they can to get the benefits of natural EPO and Red Blood Cell production. Talk to any distance runner who is an advocate and they’ll rattle off the number of sub 13 5k runners who lived at altitude and name Bob Kennedy and maybe a handful of others who did it without utilizing altitude.

Every year wanna-be distance stars flock to Flagstaff, Boulder, and Park City, Utah for the benefits of the thin air.

But, there’s more to the picture. In my experience coaching elites, I’ve had athletes who were super responders to altitude, and those who had dreadful responses, all with more than adequate iron/ferritin levels. I’ve had athletes who were bad responders early in their career but positive responders later in their career.

In the research world, we’ve called this the responder versus non-responder phenomenon. There’s some evidence that it’s linked to genetic differences and speculation that even epigenetic changes could play a role. I’ve also speculated that responder/non-responder also is dependent on dose and frequency of training, as well as an ability to adapt to the stressor that is altitude.

In my own line of work, I’ve noticed distinct trends with athletes who had high stress responses, as indicated by things like cortisol levels, as more likely to fall into the non-responder category. For instance, I had one athlete with chronically high cortisol levels and anxiety issues who despite having a ferritin level well into the triple digits, did not respond well to altitude.

Altitude and Brain Chemicals
A recent theory throws an interesting wrench into the altitude question.

Apparently, the state of Utah has a suicide and depression problem. It’s got some of the highest rates of suicide and depression and the country and for years no one understood why. Recently, a neuroscientist at the University of Utah, Perry Renshaw, has posited a theory of why this paradox occurs.

It’s the altitude.

Renshaw’s theory is that altitude causes changes in the brain chemicals dopamine and serotonin. Dopamine and Serotonin are involved in a host of actions but are most widely known in their role in mood and reward seeking. In particular, serotonin is manipulated in the most well known anti-depressants, SSRI’s, and dopamine is modulated in another form of antidepressant medication.

In the article by Theresa Fischer, she mentions that in one study, that linked psychological changes and altitude.

 In a 2005 study, the Naval Health Research Center measured mood changes in Marines who left seaside San Diego for 30 days of strenuous training in the Northern California mountains. Before training, the Marines completed a self-evaluation of their levels of anxiety, dejection, fatigue and bewilderment, among other mood symptoms. They completed the same evaluation after training ended, and then again 90 days later. While their physical fitness improved during training, their mental health disintegrated. Before training, the Marines reported more balanced mood levels than average college-aged men. By the time they finished, they described mood symptoms comparable to those of psychiatric patients. Ninety days later, they were just as sad and agitated.

When we consider training environments, this particular studies findings is somewhat disturbing.

When we bring the brain chemistry into the equation though things get really interesting. Renshaw posits that when coming to altitude, people experience an increase in dopamine and a decrease in serotonin.

What’s interesting is that some people feel better at altitude, while others suffer from the depressive like symptoms. Renshaw suggests that in these cases the increase in dopamine supersedes the decrease in serotonin, and that this likely occurs in those who are born at altitude. These are the people who move away from the mountains and yearn to be back home.

On the flip side, if the drop in serotonin levels predominate then people are more likely to feel the symptoms of depression, anxiety, and so forth.

What’s more is that, how they react depends on whether a person moved to Utah and altitude, or was born there. This could be seen as evidence for an adaptation or epigenetic component.

The point is that if Renshaw’s theory is correct, it means that those susceptible to low serotonin levels, such as those that have tendencies towards anxiety, mood disorders, depression, etc. might have a much harder time adjusting to altitude. The mood disturbances will predominate.

On the other hand, those who may need some more dopamine, but have plenty of serotonin to spare, might thrive at altitude. They might be the outdoor adventure seekers who need the high of another hit of dopamine to keep them going.

While this is a gross simplification, looking at altitude from a brain chemistry standpoint leads to some intriguing questions when we start looking at using altitude as a performance enhancer in sport.

So what?
The most obvious idea that comes to mind is that we might see positive physiological adaptations, yet have negative psychological adaptations. Perhaps this is why we can still see increases in RBC in some post altitude, but no changes or worsening performance.

To me, the take away is that maybe we need to consider the brain and psychological side of altitude training. Perhaps screening for mood traits or personality disorders/trends would be a wise step to take in addition to the physiological testing most do. It’s also quite possible that some of the correlation that I saw with high cortisol/stress levels leading to a negative or absent adaptation was simply related to those abnormal hormones being related to a mood disorder or disturbance issue.

I had always assumed that if the athlete had a high stress response, they weren’t adapting to altitude because altitude itself acted as another stressor. So when it came time to adapt to the thin air, the stress was simply too high and they had very little energy to adapt in a positive manner. While this certainly plays a role, it’s also likely that some combination of serotonin and dopamine related changes could play a role.

Whatever the case, I think it would be wise to start to consider the mental and brain chemical side of altitude living and training. In particular, those on dopamine agonist or SSRI’s might be highly susceptible to altitude.

My practical take away would be to do athlete screening using various psychological and mood state questionnaires. If we can see who might be susceptible to the psychological and chemical changes of altitude, it might allow us to better put in place methods of managing their responses.

All in all, it is an interesting theory to chew on. Hopefully it gets us to think outside of the RBC->Altitude connection and instead consider the psychological and neuro-chemical component.

Altitude could be the best or worst thing for that particular athlete. We just have to find out what type of athlete they are

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    1. […] Could altitude cause depression? […]

    2. Tom Cuddy on May 18, 2018 at 8:46 pm

      Very interesting. I recently wrote an article (for an environmental exercise physiology class) that explored the idea of altitude affecting decision making while mountaineering in Colorado. The article was basically a proposing mechanisms that may explain the number of deaths on 14ers last year. Instead of a neurochemical approach, I explored the idea of hyperventilation leading to hypocapnic vasoconstriction of cerebral blood flow and subsequent vascular resistance to the prefrontal cortex. There is so much we don’t know about altitude, cognition, and behavior!

    3. Natalie on October 8, 2018 at 2:20 pm

      I grew up at low altitude and moved to Denver when I was 18, where I began to experience depression for 16 years. I then moved to Los Angeles for two years, and my depression was in full remission. I started running and I felt like a healthy person, finally, for the first time in my adult life. Then this summer I had to move back to Denver, and since I’ve been here my depression has re-emerged with a vengeance. Running is so incredibly difficult for me here, as are day-to-day things that felt so easy in LA. I’m still running even though it’s hard, and when I traveled to do a 10K recently at sea level I felt like a superhero, I was so fast! But the depression and altitude connection is no joke, especially for women. They’ve found some promising results with creatine supplementation and hypoxia-induced depression, but it doesn’t seem to help me much yet. To anyone who cannot kick their depression at altitude, and you have the opportunity to move to sea level, do it! It’s worth it.

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