The changes in maximal oxygen uptake (V̊O_2MAX) induced by physical exertion during an Antarctic expedition depend on the initial V̊O_2MAX of the individuals: a case study of the Brazilian expedition

ABSTRACT

Antarctic climate is challenging, since the cold, wind and sensory monotony are stressful stimuli to individuals. Moreover, camp activities and heavy clothes may contribute to increase physiological strain. Thus, we aimed to characterise the physiological demand of a 24-day period in the Antarctic field and then to evaluate the effect of this expedition on the aerobic fitness in individuals with heterogeneous initial aerobic fitness (as determined by estimating maximum oxygen consumption – V̊O_2MAX). Before and after the 24-day period in Antarctica, 7 researchers and 2 mountaineers were subjected to incremental tests to estimate their V̊O_2MAX. Field effort was characterised by measuring heart rate (HR). During the field trips, their HR remained 33.4% of the recording time between 50–60% HR_MAX, 22.3% between 60–70% HR_MAX, and only 1.4% between 80 and 90% HR_MAX. The changes in estimated V̊O_2MAX during the expedition depended on the pre-expedition aerobic fitness. The post-expedition V̊O_2MAX increased by 5.9% and decreased by 14.3%in individuals with lower (researchers) and higher (mountaineers) initial V̊O_2MAX, respectively. We concluded that physical effort in the Antarctic field is characterised as predominantly of low- to moderate-intensity. This effort represented an effective training load for individuals with lower initial V̊O_2MAX, but not for those with higher V̊O_2MAX.

KEYWORDS:

• Cold
• fitness
• heart rate variability
• physical capacity
• training load

Acknowledgments

The authors would like to thank NUPAD/UFMG for the laboratory support. We thank the military group involved in the OPERANTAR for the logistical support and also to thank Professor Alexander Kellner for allowing data collection with the individuals of his research group. Very specially, we would like to thank the volunteers who, during their hard work, participated with enthusiasm and without restrictions in this study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Geolocation information

Snow Island, South Shetland Islands (62°43ʹ51.8” S, 61°12ʹ33.1” W).

Additional information

Funding

This work was supported by the edital 64/2013/ PROANTAR/MCTI/CNPq/FNDCT (Brazil), under the grant number 407803/2013-0; by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES; post-doctoral fellowship to MMM) [2248/2011]; UFMG - PRPq; by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq; research fellowship to RMEA, under the grant number 305952/2017-0); and by the Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) [CDS- PPM 000304/16].