Validity of Using Heart Rate as a Predictor of Oxygen Consumption in Dance

Abstract

The validity of predicting oxygen uptake (VO2) from heart rate (HR) was examined in 19 professional modern dancers of both genders ranging in age from 21 to 29 years. The subjects were measured on two occasions; once during a multi-stage graded treadmill test and again during their usual modern dance class. The data showed significant differences during both the treadmill test or dance class at lower intensities of less than 20 ml·kg‑1·min‑1 (p ≤ 0.03) and paradoxically no significant differences between the relationships at intensities greater than 20 ml·kg‑1·min-1. However results also identified large individual variability and when taken into account the great variability, it would seem unacceptable to predict the VO2 from HR values in dance, based on the HR-VO2 relationship established from a progressive treadmill protocol. Furthermore, given that dance is a non-steady-state activity and is executed at low to moderate intensities with occasional anaerobic bursts, it seems unlikely that the HR-VO2 relationship established from a steady-state laboratory test can be relied upon as a predictor of VO2 in dance. An understanding of the energy requirements of dance can help in the development of more effective and appropriate training programs for dancers. However because of the intermittent and random movement pattern of dance, it has been difficult to accurately measure energy expenditure during the activity itself. Attempts at measuring the energy requirements of dance in previous studies have either involved the use of Douglas bag equipment1,2 where movement restriction was noted or they have assumed oxygen uptake (VO2) values from dance heart rates (HR) on the basis that the linear relationship between HR and VO2 3,4 established in laboratory tests (treadmill or cycle ergometer) holds true for dance.1,5 Dance is considered a nonsteady- state activity6,7 and, although the indirect method of predicting VO2 from HR has been noted as reliable during steady-state activities,3,8 the extent to which the relationship can be relied upon in non-steady-state conditions is questionable.8-10 The degree to which HR and VO2 are related during activities that involve different muscle groups and changing work intensities is far from established. In 1995, Lothian and Farrally11 found that heart rate gave a close estimate of VO2 during intermittent exercise, while in 1996, Bernard and colleagues8 suggested that the method can be depended upon during non-steady-state conditions providing that individual subject relationships are used. Dance can consist of fast jerky movements, off-balance turns, twists, and falls to the floor. Dance is multi-directional and involves the use and coordination of different muscle groups at varying times. No previous research has established the validity of this method of work rate prediction in dance. The aim of the current study was to investigate the validity of the use of HR in estimating VO2 in dance from the HR-VO2 relationship established in a steady-state laboratory test.