Author: Carmen Houck
As someone who grew up in Colorado, altitude has always been a hot topic of conversation. From people coming to visit and mentioning how they tire quickly to experiencing the difficulty to breathe while climbing 14ers (14,000+ foot peaks), it is a topic that came up
frequently among friends and family. As I got older and started learning more about how the body works, I started seeing the science and rationale behind all those conversations I had growing up. For most people, high altitude just means it’s harder to breathe, but why?
The reason that it feels harder to breathe at higher altitudes and elevations is that your body is essentially getting less oxygen per breath you take. The percent of oxygen in the air doesn’t change, but since atmospheric pressure decreases as you go up to higher altitudes, the partial pressure of oxygen is also decreasing. Along with this decrease in partial pressure, the body’s driving force for getting oxygen from your lungs to blood is lessened, so the body often compensates by hyperventilation, which results in your muscles used for breathing to work harder. All these factors contribute to feelings at altitude such as breathlessness, tiring quickly, and headaches. Additionally, hypoxia is referred to as the state of less oxygen reaching your brain and the rest of your body.
Due to these adaptations in breathing the body has to make at higher altitudes, I heard that those who live at high altitudes perform better at lower altitudes. That made me think, why don’t Colorado sports teams always win then? When looking at the research, what we find is…it depends. Training at high altitude, also known as hypoxic conditions, can affect your performance at low altitude, but the effects vary. The biggest difference is in whether you are doing an aerobic or anaerobic activity. Aerobic activities involve oxygen for energy sources, like endurance sports or running. Anaerobic activities are not reliant on oxygen for energy and are often power sports, like lifting weights. However, many activities use a mixture of the two, so we have to look at those as well.
When it comes to studying the effects of altitude training, most research focuses on endurance runners. It has been concluded training at higher altitudes can improve one’s low altitude performance (Stray-Gundersen et al., 2001). The runners of the study saw a decrease in time trials and an increase in VO2max, meaning they were running faster and breathing more efficiently. They also discovered that those who trained at high altitudes were able to deliver more oxygen to their peripheral tissues after training. Though this was conducted on elite athletes, the training effects would likely have positive effects on amateur runners as well.
If we look at the other end of the spectrum, sprinting, a very anaerobic sport, research also supports training in hypoxic conditions. Kasai et al. (2001) found altitude training resulted in an increase in power output during sprint performance among college athletes. This means that training in hypoxic conditions improved sprint performance. This was due to an increase in the contribution of anaerobic energy supply or getting more energy from systems that do not use oxygen. However, when we look at a study done about another largely anaerobic activity, isometric strength, there was no effect due to hypoxia training (Morales-Artacho et al., 2018). Finally, it was found resistance circuit training, which is also anaerobically based, hypoxia training is seen as beneficial (Álvarez-Herms et al., 2016). Those who did resistance training in hypoxic conditions saw an increase in red blood cell content and higher peak blood lactate. This means that they can deliver more oxygen to their tissues and can also work harder for longer. This overall, contributed to an improvement in anaerobic performance.
The conclusions to research are a little bit scattered, with different results for different activities. The change in altitude affects the body because of the amount of oxygen the body is getting, so therefore it would affect activities that need oxygen for energy production the most. This aligns with the research in that there would be a great effect in endurance running because their oxygen use is being stressed and challenged at altitude. Conversely, it makes sense that there is more of a mixed result with anaerobic activities because they are less reliant on oxygen for success, so training at altitude is not induing the stress in the same way. While more evidence would help draw concrete conclusion, what does this mean for people who want to improve their performance in a sport or activity? Does altitude training help performance at low altitude? From what we understand currently, the answer seems to be that it can’t hurt. With performance improving for most conditions, if you are looking for a boost in performance, hypoxia training or altitude training might be worth a try.
Sources:
Kasai, N., Mizuno, S., Ishimoto, S., Sakamoto, E., Maruta, M., & Goto, K. (2015). Effect of training in hypoxia on repeated sprint performance in female athletes. SpringerPlus, 4(1). doi:10.1186/s40064-015-1041-4
Morales-Artacho, A. J., Padial, P., García-Ramos, A., Pérez-Castilla, A., Argüelles-Cienfuegos, J., Fuente, B. D., & Feriche, B. (2018). Intermittent Resistance Training at Moderate Altitude: Effects on the Force-Velocity Relationship, Isometric Strength and Muscle Architecture. Frontiers in Physiology, 9. oi:10.3389/fphys.2018.00594
Stray-Gundersen, J., Chapman, R. F., & Levine, B. D. (2001). “Living high-training low” altitude training improves sea level performance in male and female elite runners. Journal of Applied Physiology, 91(3), 1113-1120. doi:10.1152/jappl.2001.91.3.1113
Álvarez-Herms, J., Julià-Sánchez, S., Corbi, F., Pagès, T., & Viscor, G. (2016). A program of circuit resistance training under hypobaric hypoxia conditions improves the anaerobic performance of athletes. Science & Sports, 31(2), 78-87. doi:10.1016/j.scispo.2015.08.005