Altitude Training

What Methods Really get you Ready to Compete? Altitude training is a controversial topic in the exercise science world. A search of the literature yields mixed results and various methods for studies and application. The concept of altitude training is to expose the body to lower partial pressure and O2 content to trigger adaptations that enhance aerobic capacity. However, it is clear that not all individuals respond the same to altitude exposure, and there does not yet seem to be a trick to determining who will over-respond, under respond, or have to respond at all.

Ascending to altitude to train might sound like an easy way to enhance O2 delivery. However, the drastic change in O2 levels necessitates training at a lower intensity. If the intensity is too low, the training stimulus is not strong enough to enhance performance but instead will result in detraining (Sims, 2002). Borden (1998) determined that training at high altitudes above 3000m shows detraining in VO2 max at sea level, likely due to an inability to maintain adequate training intensity at such high altitudes. In comparison, Anderson (2014) tested sprint kayakers training at moderate altitudes, 915m-2000m, and did find an improvement in VO2 max at sea level. Both studies by Borden (1998) and Anderson (2014) support the notion that high altitude training above 2000m is not conducive to sea level performance enhancement.

There are a few methods around this detraining side effect of high altitude training that are gaining interest. The first is the concept of training at a lower altitude, 1500m or less at high intensities but living at an altitude above 2000m. This can be done by physically living at a higher altitude or in a simulator that mimics the partial pressure of altitudes above 2000m. For training or living, the minimum threshold for high altitude to elicit favorable performance responses is 2000m (Simms &Reuter, 2002). The downside of this method is that it is not always attainable for various reasons; commuting time, long term living in an altitude chamber, cost, etc.

Recently there has been a push to find a way to make hypoxic training more attainable for athletes. This search has resulted in the use of altitude masks that can be used at rest to expose the body to lower partial pressure to trigger the secretion of erythropoietin (E), leading to a higher synthesis of red blood cells to transport more O2. Mikulski et al. (2014) conducted a study using an altitude mask to trigger E secretion in endurance athletes. While this study did conclude that after just four days of hypoxic training, E secretion increased significantly, the success of this study was likely the specific hypoxic expose of every athlete. Before conducting trials, Mikulskli et al. tested each athlete's hypoxic threshold to ensure that their blood O2 never dropped to levels unconducive to the instructed exercise intensity during the study. While this method is ideal, it is undoubtedly not possible during a training session in the field.

Interestingly, the hypoxic conditions that can lead to detraining in aerobic athletes do show some possible benefits to enhancing aerobic capacity in anaerobic athletes. While anaerobic athletes mostly rely on energy production without O2, also utilizing O2 for energy can enhance performance in events over two minutes but under 10 minutes. However, traditionally aerobic conditioning has proven inappropriate for anaerobic athletes because the need to train long-duration and low-intensity results in recruitment patterns away from power production, limiting anaerobic performance (Borden, 1998). Maintaining short-duration, high-intensity drills at altitude does not appear to result in the same inability to maintain intensity as long-duration exercise at altitude (Borden, 1998). This finding, however exciting and with possible promise, does not yet have substantial support.

Considering all of these factors, the best way to enhance performance with altitude would be to use moderate altitude for endurance athletes. Moderate altitudes would likely lessen the contraindications that some individuals experience with high altitudes and the detraining effect. Moderate altitude also lessens the range in response that individuals experience at high altitudes and allows athletes to adapt in similar ways to their peers mostly. However, reaching even moderate altitude might not be possible for athletes who live at sea level without the ability to climb to train.

While hypoxic masks are gaining popularity, in a field setting outside of experimentation, there is no way for an athlete to monitor or know their hypoxic limit to ensure adequate O2 intake to maintain the required intensity. This inability to individualize this training also puts athletes at risk for negative physical symptoms associated with decreased O2 levels. Considering these two factors, I do not believe that masks provide justifiable or reliable performance enhancements in a field setting.

I would be interested in finding more science on the benefits of hypoxic training for anaerobic athletes. However, at this time, with the research that I have, I feel that the inability to determine who will and won’t adapt and the risk of an athlete experiencing a contraindication lead me not to recommend this modality.

In conclusion, I do not believe that this modality offers justifiable performance gains without the ability to determine a hypoxic threshold specific to the athlete and time to evaluate how individuals respond to higher altitudes. Now, for athletes that must compete at higher altitudes, I would encourage them to spend time acclimating to higher altitudes before the competition.

References

Anderson, R.D. (2017) Altitude training as a mean to improve sea level performance in elite level sprint kayakers. Journal of Australian Strength & Conditioning, 25(7), 33-37.

Borden, R. (1998). The high altitude sports training complex not just for endurance athletes. Strength & Conditioning, 20(3), 64-69.

Mikulski, T., Dabrowski, J., & Krzywanski, J. (2014). Altitude training at sea level and its impact on epo and vegf. Medicinia Sportiva, 18(3), 84-87.

Power, S.K., & Howley, E. T. (2018) Factors Affecting Performance. In Exercise physiology: Theory and application to fitness and performance (10th ed., pp. 442-457). Essay, McGraw-Hill Education.

Sims, S. & Reuter, B. (2002). Interval hypoxic training: Altitude adaptation at sea level. Strength & Conditioning Journal, 24(6), 42-44.