Altitude training for performance enhancement: does it work?
Many athletes adopt high altitude training to improve performance. It is well established that training at altitude improves endurance performance when competing at altitude. However, if it is the goal to improve sea level performance the literature is controversial. The most utilized training modality is the live high train low training concept (LHTL). Athletes performing this type of training live at altitude (2000-2500m) for several weeks (3-4 wks) and train close to sea level. Living at altitude (min 12-14 hr/d) is intended to increase the total hemoglobin mass (tHBmass), while training at sea level keeps training quality high. This concept was recently challenged, showing that elite athletes with already high tHBmass will not further increase their oxygen carrying capacity and thus will not improve performance. In the literature, these findings led to a scientific debate mainly because LHTL was considered the “gold standard” for altitude training with no final answer yet. During the last years, additional high altitude training strategies were introduced. With the development of new approaches, the focus shifted from solely considering endurance athletes to including game sport athletes as well. This led to the development of the repeated sprint training in hypoxia (RSH) concept and furthermore to the combination of LHTL with RSH named live high train low and high (LHTLH). RSH consists of performing multiple sets (3-4, rest 3-5min) of repeated (n=4-7) short (4-15s) maximal sprinting bouts, interspersed with <30s of rest between intervals. Performing RSH was found to improve the ability to perform repeated sprints, which is considered a crucial ability in many intermittent sports (e.g., soccer, tennis). The performance improvements were mainly linked to an increased muscle blood flow, especially to the fast-twitch fibers and changes in the energy pathway and buffer capacity. However, similar to LHTL, the RSH concept was challenged in recent years, which also led to a scientific debate with no final answer yet. In summary, from a scientific point of view, the effectiveness of high altitude training to improve sea level performance can be neither proofed right nor wrong at present. The readers and practitioners are encouraged to critically assess the strength and weaknesses of the different studies and to form their own opinion. From a practical viewpoint, coaches and athletes should decide according to their experience and beliefs whether to implement high altitude training concepts in their training routine.