In 1973, Sir Roger Bannister said that no clear proof of benefit of altitude training
had emerged during a panel discussion on this topic, published in BJSM.1 What have
we learnt in the intervening 40 years?
Altitude training—what use in team sports?
To date, most altitude training research is oriented towards individual endurance
athletes, while the potential benefits for team sports remain largely unexplored.
Hence, the safety and equality aspects of competitive football matches held above
2500 m have been passionately debated for over two decades.2 In 1993 this debate was
invigorated when Brazil lost its first qualification game for a World championship
in the stadium of La Paz (Bolivia), located at an altitude of ∼3600 m. Undoubtedly,
the altered environment at altitude had a significant impact on players physical performances,3
and some athletes were better able to cope with the change in altitude than others,
especially those who were better acclimated.4 Recently, the fact that Argentina suffered
their worst loss in 60 years, a sound defeat of 6-1 against host Bolivia in a South
Africa World Cup qualifier, clearly demonstrates that playing international games
at altitude is a major challenge.
Despite the apparent lack of strong scientific evidence, it is striking to observe
that altitude-training centres have been established around the globe, and are now
offering team sport players the opportunity to train under sport-specific hypoxic
conditions. Girard et al
5 have shown how sprinting and small-sided games can be performed inside inflatable
hypoxic marquees. Today, concepts regarding the use of hypoxic methods for team sport
players are evolving.6 Owing to the widespread belief that altitude training confers
a competitive advantage, this topic has an unprecedented popularity in the team sport
community.
This issue
In this themed issue, Aspetar (Qatar Orthopaedic and Sports medicine Hospital) partners
with BJSM to provide the journal's readership with a representation of the current
research into altitude training and team sports. As the chair of the scientific committee
of the Altitude Training and Team Sports Conference, I am proud to be guest editing
this issue, in which we present current updates and original investigations authored
by international experts in this bourgeoning field.
Current updates
The current updates section starts with a comprehensive summary of the factors that
affect either sprint performance or the ability to recover from maximal or near-maximal
efforts at sea level, and discusses the evidence that these may be improved by altitude
training.7 Billaut and Aughey8 then illustrate the adverse effects of acute altitude
exposure on single-sprint and repeated-sprint capacity. The authors conclude that
players displaying enhanced muscle reoxygenation capacity, greater buffering power
and maintained cerebral oxygenation should better cope with the stress of altitude.
Changes in haemoglobin mass reflect major systemic adaptations. Saunders et al
9 postulate that an ∼1% increase in haemoglobin mass results in a 0.6–0.7% increase
in maximal oxygen uptake in most elite endurance athletes after various forms of altitude
training. Gore et al
10 present a meta-analysis (17 studies) of papers having used the carbon monoxide
rebreathing technique to determine haemoglobin mass. A key feature of their review
is their demonstration that classical altitude training camps as short as 2 weeks
are likely to increase haemoglobin mass and benefit most athletes.
Chapman11 explains the importance of screening arterial oxyhaemoglobin saturation
and hypoxic ventilatory responses in order to determine how team members might individually
respond to hypoxic conditions. Readers are provided with overwhelming evidence promoting
the individualisation of adjustments in exercise intensity and/or duration at altitude.
Faiss et al
12 critically analyse the results of studies involving high-intensity exercise performed
in hypoxia for sea-level performance enhancements, by differentiating intermittent
hypoxic training and repeated sprint training in hypoxia.
Original investigations
The first set of original investigations deals with the various aspects of altitude
exposure in three different team sports. First, McLean et al
13 show that two consecutive preseason moderate altitude camps yield a similar (4%)
increase in haemoglobin mass in elite Australian footballers, while they do not change
their haemoglobin mass consistently from year to year. Buchheit et al
14 demonstrate that, compared with training in the heat-only, an additional hypoxic
stimulus during sleep and particular training sessions has no high-intensity running
performance benefit, immediately after a 14-day off-season camp in professional Australia
football players. In a group of rugby players, Harvey et al
15 report that 12 repeated-sprint training sessions in hypoxia resulted in a twofold
greater improvements in the capacity to perform repeated high-intensity aerobic work
than equivalent normoxic training. Finally, Garvican-Lewis et al
16 highlight that 10 days of simulated ‘living high-training low’ altitude training
increases oxygen transport capacity in elite female water polo players by 3–4%, which
is strongly related to specific aerobic fitness.
In the final set of papers of the supplement,17–21 the International Study on Football
at Altitude 3600 m (IFA3600) is presented with the intention of documenting, first,
the extent to which running performance is altered at 3600 m as compared with sea-level
and, second, the time-course of acclimatisation of both physical performance and the
underlying physiological adaptations associated with training and playing at 3600 m
(sea-level native players) and at low altitude (high altitude-adapted players). Specifically,
of a series of seven companion papers attempting to quantify the acute and chronic
effects of competing at La Paz, Bolivia (3600 m) on game and training running performance,
acclimatisation, haematology and sleeping patterns of national-level junior players,
five are published in this supplement. The two remaining papers can be found in a
regular issue of BJSM.21
22
Finally, the culminating point of this supplement is perhaps the position statement
featuring scientifically based strategies that may be of importance to consider when
intending to implement altitude training with team sport players.23
What are the new findings?
Forty years after the publication of the initial altitude training issue in this journal,1
major advances have been made from a performance and mechanistic perspective.
The three main points are
The current level of evidence for the efficacy of hypoxic methods to improve exercise
performance at moderate or high altitude (acclimatisation) is well established. However,
the benefits of using a ‘living high-training low’, ‘Living high-training high’ and
‘living low-training high’ altitude-training intervention or a combination of those
methods to improve team sport-related physical performance on return to sea level
are not as definitive.
Training camps as short as 2 weeks can increase haemoglobin mass substantially in
a range of professional team sport players, while limited data currently exists regarding
the time course of non-haematological adaptations.
It is undeniable that no single recommendation is likely suitable for all players
in a team, or across all team sports, requiring the development of optimised interventions
at the individual player level.
Finally, the physiology underlying altitude-related effects on physical performance
in many team sports is still far from fully understood.