A simple approach to assess VT during a field walk test

• Processo: 10/12614-5
• Modalidade de apoio: Auxílio à Pesquisa - Publicações científicas - Artigo
• Data de Início da vigência: 01 de setembro de 2010
• Data de Término da vigência: 28 de fevereiro de 2011
• Área do conhecimento: Ciências da Saúde - Fisioterapia e Terapia Ocupacional
• Pesquisador responsável: Victor Zuniga Dourado
• Beneficiário: Victor Zuniga Dourado
• Instituição Sede: Instituto de Saúde e Sociedade (ISS). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brasil
• Assunto(s): Teste de esforço Variabilidade da frequência cardíaca Teste de caminhada Publicações de divulgação científica Artigo científico
• Palavra(s)-Chave do Pesquisador: exercise testing | Heart rate variability | Shuttle walk test | Fisiologia do Exercício

Resumo

We aimed to examine whether the ventilatory threshold (VT) during an incremental shuttle walk test (ISWT) could be determined using heart rate variability (HRV) analysis. Further aims were to assess variables capable of predicting performance in the ISWT and the intensity of this test. Beat-to-beat RR intervals and gas exchange values in 10 healthy subjects (31-83 years; 7 men) were collected during the ISWT. The ventilatory equivalent was used to assess VT from respiratory components. To determine the HRV threshold (HRVT), the instantaneous beat-to-beat variability values of the RR intervals in each stage of exercise were graphically plotted against walking speed (WS). The oxygen consumption at HRVT was calculated (VO2HRVT). No significant differences were found between walking speed (WS) at VT and WS at HRVT (5.04 ± 1.00 vs. 5.10 ± 1.04 km/h; p = 0.89). Linear regression analysis revealed a strong correlation between VO2VT and VO2HRVT (r2 = 0.896). The Bland and Altman plot analysis revealed an agreement between VO2VT and VO2HRVT (-0.05; 95%CI: -0.30 to 0.20 L/min). Thus, the VT can be assessed during the ISWT using a simple heart monitor. The ISWT may be a useful tool to assess exercise capacity and prescribe walking programs. (AU)