Altitude And Endurance Performance
by Doug Stewart
Who has a natural advantage – Altitude Natives or Lowlanders?
The Tour de France is in full swing and as they are approaching the mountains it is a good time to pick up on the topic of Altitude. It is not just in the Tour de France, but in almost all professional cycling stage races that intense efforts at high altitude are required.
If cycling at very high speeds, altitude can help performance as the higher above sea level, the lesser the air density and the aerodynamic drag. That is the reason why 1-hr world record attempts are typically done at altitude. (The current male record is from April 16, 2019: Victor Campenaerts cycled 55.089 km in Aguascalientes, a city in Mexico at around 3,000 meters above sea level).
However, altitude comes with the disadvantage that there is less oxygen to breathe due to lower air pressure and this also means less oxygen supply to working muscles. At lower cycling speeds, that physiological limitation outweighs the benefits coming from aerodynamics (such as cycling uphill in a road race versus a flat track race/record attempt). Hence, a lot of research has been done on how to minimise that detrimental effect / how to adjust best to altitude.
It is well documented that high-altitude native populations have adapted to the hypoxic environment they have been living in for generations – they have a higher maximal oxygen uptake (VO2max) and a better endurance performance at altitude than lowlanders.
An interesting question is why exactly that is the case and whether altitude acclimatisation can help lowlanders match the exercise capacity of altitude natives when performing at altitude.
There is a body of research out there, but most of these studies were done on nonathletes (e.g., Lundby et al, Calbet et al, Wagner et al). For the first time, a group of researchers from Italy analysed the influence of altitude on real-world cycling performance in top-level professional cyclists and checked the difference whether they were altitude natives or not. Their results are quite interesting. In a nutshell, altitude natives have an advantage, particularly in races including efforts at >1,500 meters above sea level. This is true even when lowlanders acclimatised to the altitude for around 2 months.
For this, they studied thirty-three male cyclists with an average age of 29 and classified them as lowlanders or altitude natives. Both groups included top 3 finishers in the general classification of Grand Tours and major races. They looked at training and race data during years 2013–2020 and investigated participants’ mean maximal power (MMP) for efforts lasting 5 s, 30 s, 5 min, and 10 min, respectively, at altitudes ranging from 0–500 to >2000 meters above sea level.
They found a significant altitude–MMP interaction effect in the lowlanders but not in altitude natives. In lowlanders, individual performance decreased with increasing altitudes compared with sea or near-sea level. This trend was much less evident in those living at high altitude. The difference for MMP for all durations was found to be even bigger at higher altitudes (≥1500 meters above sea level). The data did not show a large enough effect of altitude training for lowlanders to match the performance in hypoxic conditions of their altitude native counterparts.
The study has 2 limitations, however. Firstly, the lowlanders registered a lower number of training hours at the highest altitude compared with altitude natives. Secondly, the study did not assess in depth the potential benefits of altitude acclimatisation in lowlanders. But despite this, it became clear that acute exposure to altitude negatively influences the performance in lowlanders but not in altitude natives. That negative effect was visible already at low altitudes (500-1000 meters above seal level) and became more evident at higher altitude.
So, if you are a lowlander and want to perform in the best possible way, you may want to select a race close to sea level in order to avoid being negatively impacted by the altitude. If you pick a race at altitude, then you may optimise your performance by doing altitude training. However, despite the training, it looks like you still will be at a disadvantage compared to altitude natives.
References:
MATEO-MARCH, MANUEL1,2; MURIEL, XABIER3; VALENZUELA, PEDRO L.4; GANDIA-SORIANO, ALEXIS5; ZABALA, MIKEL6; BARRANCO-GIL, DAVID1; PALLARÉS, JESÚS G.3; LUCIA, ALEJANDRO1,4 Altitude and Endurance Performance in Altitude Natives versus Lowlanders: Insights from Professional Cycling, Medicine & Science in Sports & Exercise: July 2022 - Volume 54 - Issue 7 - p 1218-1224. doi: 10.1249/MSS.0000000000002890
Lundby C, Calbet JA, van Hall G, Saltin B, Sander M. Pulmonary gas exchange at maximal exercise in Danish lowlanders during 8 wk of acclimatization to 4,100 m and in high-altitude Aymara natives. Am J Physiol Regul Integr Comp Physiol. 2004;287(5):R1202–8
Calbet JA, Robach P, Lundby C, Boushel R. Is pulmonary gas exchange during exercise in hypoxia impaired with the increase of cardiac output? Appl Physiol Nutr Metab. 2008;33(3):593–600
Wagner PD, Araoz M, Boushel R, et al. Pulmonary gas exchange and acid-base state at 5,260 m in high-altitude Bolivians and acclimatized lowlanders. J Appl Physiol (1985). 2002;92(4):1393–400