Reliability and validity of heart rate variability threshold assessment during incremental shuttle-walk test in middle-aged and older adults

• Grant number: 12/20691-5
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: December 01, 2012
• End date: May 31, 2013
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Victor Zuniga Dourado
• Grantee: Victor Zuniga Dourado
• Host Institution: Instituto de Saúde e Sociedade (ISS). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brazil

Abstract

Studies on the assessment of heart rate variability threshold (HRVT) during walking are scarce. We assessed the reliability and validity of HRVT assessment during the incremental shuttle walk test (ISWT) in healthy subjects. Thirty-one participants aged 57±9 years (17 females) performed 3 ISWTs. During the 1st and 2nd, instantaneous heart rate variability was calculated every 30 s and HRVT was identified. Walking velocity at HRVT in these tests (WV-HRVT1 and WV-HRVT2) was registered. During the 3rd ISWT, physiological responses were assessed. The ventilatory equivalents were used to assess ventilatory threshold (VT) and the WV at VT (WV-VT) was recorded. Between WV-HRVT1 and WV-HRVT2 the difference was non-significant (median and interquartile range: 4.8; 4.8_5.4 vs. 4.8; 4.8_5.4 km.h-1); the correlation was significant (r=0.84); the intraclass correlation coefficient was high (0.92; 0.82_0.96) and the agreement was acceptable (-0.08 km.h-1; -0.92_0.87). Considering WV-VT and WV-HRVT2 the difference was non-significant (4.8; 4.8_5.4 vs. 4.8; 4.2_5.4 km.h-1) and the agreement was acceptable (0.04 km.h-1; -1.28_1.36). HRVT assessment during walking is a reliable measure and enables the estimation of VT in adults. We suggest the use of the ISWT for the assessment of exercise capacity in this age group. (AU)