Abstract 16312: Work Physiology Revisited

Abstract

Background: Evidence supports a robust inverse association between cardiorespiratory fitness and all-cause mortality. Prior research assessing cardiorespiratory fitness data and the correlation between these variables tend to use peak oxygen uptake, indirect measuring methods and selected populations. Purpose: The aim of this study was to provide a large reference material on exercise physiology data in a healthy mixed sex population age 20-90 years.

Methods: Data in the HUNT 3 fitness study was obtained from a representative cross-section of volunteering Norwegians consisting of 1929 males and 1881 females, and was collected from June 2007 to June 2008. VO2max, maximal heart frequency, O2 pulse and workload was measured during treadmill running. O2 pulse was measured at 3 different work intensity levels including maximum work capacity, and subjective perception of fatigue (Borg scale: 6-20) was stated at each level. The physical activity index score (PAI) was calculated from the candidates response to a questionnaire.

Results: The highest VO2max and heart rate among males and females was found in the youngest age group and was 54.4 ± 8.4 mL•kg-1•min-1 and 43.0 ± 7.7 mL•kg-1•min-1 (gender differences, p<0.001) and 196 ± 10 beats•min-1 and 194 ± 9 beats•min-1 (gender differences, p<0.05), respectively, with a subsequent reduction of approximately 1 MET and 6 beats•min-1 per decade. The highest O2 pulses are displayed in the 3 youngest age groups among males and females, 22.3 mL•beat-1 ± 3.6 and 14.7 mL•beat-1 ± 2.7 (gender differences, p<0.001), respectively, with no significant difference between these age groups. Following age groups display an 8% reduction per decade among both genders. Reported Borg scores appear to give a good estimate of the relative exercise intensity. The youngest age group, both males and females, presented physical activity index score (PAI) considered to indicate a high level of physical activity, whereas all other groups displayed PAI scores indicating moderate physical activity.

Conclusion: The HUNT 3 fitness study provides reference values on a range of exercise physiological parameters in a large healthy population age 20-90 years. It also displays associations between physiological variables.