Validation Of Three Indirect Vo2max Assessments At 2600 M Altitude In Young, Sedentary Adults

Introduction
Indirect determinations have acquired a relevant role when there is need to evaluate the cardiorespiratory fitness of
groups or individuals not engaged in elite sports, or when access to direct measurements is limited. There has been
extensive work validating indirect tests in different populations reporting good correlation between direct and indirect
measurements. Most studies have been done at sea level [1,2,3,4,5] and, to our knowledge, few references [6,7] can be
found in the literature addressing the validity of indirect tests at different altitudes.
hypobaric hypoxia causes a significant reduction of vo2 max above 1500 meters. acute and chronic exposure to altitude
has shown a decrease in v02max [](6, 9, 14, 39, 42) that can be attributed to partial compensation mechanisms for a decrease in
oxygen delivery to working muscle. it is not clear to what extend previous validation studies for indirect tests,
performed at sea level, can be extrapolated to moderate altitude acclimatized populations.
Aiming to evaluate validity of these indirect tests at a moderate altitude we studied a group of young, healthy, sedentary
adults, living at 2600 m, to determine the correlation between the direct v02max ergoespirometric measurement, two
widely used exercise indirect methods (ukk walk test [2], 20-mst [1]) and one indirect non-exercise method (pfa-par)
[3]in order to validate them at a moderate altitude.

Methods
sixty-four (34 men and 30 women) apparently healthy, non-obese medical school, volunteer students, were evaluated at
the national high performance and altitude research center, at bogotá, colombia. Subjects (aged 18 to 26 yr) initially
underwent a preparticipation medical evaluation. then, fasting blood samples were obtained for determination of
hemogram, lipid profile and glycemia. initially, participants answered a perceived functional ability-physical activity
rating (pfa-par) questionnaire.
direct cardiorespiratory fitness was determined using a using a mixing chamber method by a monitored, maximal
incremental treadmill protocol, until vo2max criteria were achieved. on a different day of the same week two field-tests
(20 m shuttle-run test and ukk walk test) were performed on a 400 m synthetic athletic track with a two hour recovery
period between both tests. intraclass correlation coefficient was obtained to establish the consistency between the three
indirect and the direct vo2max measurement

Results
direct vo2max was 41.2 ± 5.8 ml•kg-1•min-1 in men and 32.2 ± 3.6 ml•kg-1•min-1 in women. the strongest correlation was
found for the 20 m shuttle run test (r= 0.90; 95% ci 0.83 to 0.94), followed by the ukk walk test (r= 0.81; 95% ci 0.69 to
0.89) and the (pfa-par) questionnaire (r= 0.77; 95% ic 0.63 to 0.86).
stratified analysis by gender showed significant correlations in men’s for the 20-mst (r=0.70 p<0.05), the ukk walk test
(r=0.48 p<0.05), the (pfa-par) questionnaire (r=0.43 p < 0.05) and in women’s the 20-mst (r=0.44 p< 0.05);
hemoglobin concentration showed a correlation with direct vo2max value (r= 0.59; 95% ci 0.39 to 0.73).

Discussion/conclusions
Out of the 3 indirect tests, the 20 m shuttle-run test showed the best correlation with direct ergospirometric values of
vo2max. We believe the results from the present study add scientific support for the application of indirect tests in the
design, evaluation and monitoring of physical activity and sport programs in large, urban populations living at moderate
altitude.
Accurate v02max estimation by indirect exercise and non-exercise tests can be made in young male’s residents at
moderate altitudes. Whether these findings can be extrapolated to female populations needs further evaluation.

References
[1]. LEGER, L., AND LAMBERT, J. (1982). MED. SCI. SPORTS EXERC. 49:1-12.
[2]. Oja, P., et al. (1991). Int. J. Sports Med. 12:356-362.
[3]. GEORGE, J., ET AL. (1997). MED. SCI. SPORTS EXERC. 29:415-423.
[4]. GRANT, S., ET AL. (1995). BR. J. SPORTS MED. 29:147-152.
[5]. Stickland, M. K., et al. (2003). Can. J. Appl. Physiol. 28:272-282.
[6]. AHMAIDI, S. B., ET AL. (1993). CHEST. 103:1135-1141.
[7]. GONZALEZ, R., ET AL. (1989) ARCH. INST. CARDIOL. MEX. 59:273-278.
[8]. Schmidt, W., et al. (2002). Med. Sci. Sports Exerc. 34:1934-1940.
[9]. Böning, D., et al.(2001). Int. J. Sports. Med. 22:572-578, 2001.

NOTA: O texto com a iconografia está no anexo.

Arquivo