There is no doubt that if you want to compete at altitude, you will first have to acclimatize to the lack of oxygen. If not, you will probably not perform as well as you could and you will certainly put your health at risk. However, does training at altitude help you to perform better at sea level? The jury is still out…
Lorenzo Pugliese and colleagues have published the latest article about this question in the September issue of the Journal of Sports Science & Medicine. It is an observational study of two elite endurance athletes, a race walker and a marathon runner, who used altitude training as part of their preparation for the Athens Olympic Games (2004). As both of them obtained gold medals, it must have worked for them, even though we do not know for sure what would have happened if they had stayed at sea level.
Even though altitude training is popular between endurance athletes and coaches, it is still controversial between scientists. In theory it should work of course: as the air pressure is lower at altitude, your body learns how to use oxygen more effectively, what then allows you to perform better when you are back at sea level. The best known effect is an increase in red blood cells, and thus in haemoglobin mass, although there are also adaptations at the level of the muscles and the mitochondria. This increase is triggered by the hormone erythropoietin or EPO, which is produced by the kidneys. However, some people produce less EPO than others and there are therefore important inter-individual differences between the effects of altitude on athletes.
Training hard and altitude
If you want to win endurance races, you need to be able to train at fast paces. Running fast for a long distance is difficult to do at altitude when you are not used to it, as your muscles need more oxygen than you can deliver to them. This is even more so for elite athletes, whose muscles are trained to perform at an optimal level. If you do not train intensively enough for a period of a time, your muscles become detrained, and anything you might have gained by improving your oxygen metabolism will be useless.
While you are acclimatizing, you will face some other problems:
- Sleeping can be difficult as you are short of breath.
- As soon as you arrive at altitude, your plasma volume (=the water part of your blood) will decrease, as your body wants to increase the red blood cell concentration and producing new red blood cells takes some time.
- The air is colder and drier which can easily lead to dehydration.
- As your muscles cannot extract as much oxygen from your blood as they do at sea level, your VO2max is in effect reduced. Running at the same speed as at sea level will therefore mean working at a higher level of your VO2max, which will feel harder.
- You are more vulnerable to infections.
All these factors will make it difficult to train at the required level during the acclimatization. Once you are used to the altitude the situation will improve, but in the meanwhile you might have lost valuable time and your legs might have lost speed.
Athletes and coaches have therefore developed live-high-and-train-low camps, whereby they live at altitude and train at lower level. Alternatively, they might do live-low-and-train high camps, whereby they perform some of their sessions at altitude to have an additional training stimulus.
Reasons for the controversy
Studies about altitude training contradict each other, whatever formula they use (live-high-and-train-high, live-high-and-train-low or live-low-and-train-high). It is of course possible that athletes and coaches have noted some benefits that are too small to be measured by scientists. As major championships are won or lost by seconds, such very small benefits can make a big difference indeed.
It more likely that the controversy is due to a lack of control groups: in a good study you would compare similar athletes doing the same training at altitude as at sea level, and you would take into account that some people do not react as well as others. In practise such a study is very difficult and expensive to conduct. To complicate matters even further, there could be a placebo effect, as most athletes believe that altitude training is beneficial.
Lorenzo Pugliese’s athletes followed a live-high-and-train-high program. However, they were able to train at the same running/walking pace as at sea level and, according to Pugliese, this is the reason why the camp worked so well for them. Both of them had extensive altitude training experience and that might well have been the reason for their success. Maybe a three week camp so now and then is simply not enough, and you might need to live for a long time at altitude to reap the benefits? This would explain why so many top endurance athletes are born and/or live at altitude. Bad news for all of us who live at sea level though…
D M Bailey and B Davies. Physiological implications of altitude training for endurance performance at sea level: a review. Br J Sports Med. 1997; 31:183-190.
L Pugliese, FR Serpiello, GP Millet et al. Training dairies during altitude training camp in two Olympic champions: an observational case study. J Sports Sci Med. 2014; 13(3):666-672. eCollection 2014.