Validity of the modified shuttle walk test to assess cardiorespiratory fitness after exercise intervention in overweight/obese adults with primary hypertension

ABSTRACT

The study aimed to assess whether the Modified Shuttle Walk Test (MSWT) can detect changes in cardiorespiratory fitness (CRF) in overweight/obese people with hypertension (HTN) after an exercise intervention evaluating the equation presented in the previous research by Jurio-Iriarte et al. Participants (N= 248) performed a peak cardiorespiratory exercise test (CPET) and MSWT before and after 16-weeks of different types of aerobic exercise intervention. The formula of Jurio-Iriarte et al. was used to predict peak oxygen uptake (V̇O_2peak). The correlation between measured and predicted V̇O_2peak was strong (r= 0.76, P< 0.001) with a standard error of estimate (SEE) of 4.9 mL·kg⁻¹·min⁻¹; SEE%= 17%. The intraclass correlation coefficient indicates a moderate level of association and agreement (ICC= 0.69; 95% CI 0.34–0.82; P< 0.001) between the measured and predicted V̇O_2peak. When analyzing obese participants alone (N= 128), MSWT equation was more accurate compared to the whole sample (ICC= 0.76; 95% CI 0.52–0.87). The relationship between the change of measured and predicted V̇O_2peak at follow-up was weak (r= 0.42, P< 0.001) with a 31% SEE, and a low level of association and agreement (ICC= 0.31; 95% CI 0.06–0.49; P< 0.001). In conclusion, although MSWT does not accurately predict CRF in people with HTN after exercise intervention and questions its validity, the new equation may have practical application to estimate V̇O_2peak for obese people with HTN when CPET is not available.

Abbreviations: AC: Attention Control; BM: Body Mass; BP: Blood Pressure; CI: Confidence Interval; CRF: Cardiorespiratory Fitness; CPET: Cardiopulmonary Exercise Test; HTN: Primary Hypertension; HR: Heart Rate; HV-HIIT: High-Volume and High-Intensity Interval Training; ICC: Intraclass Correlation Coefficient; LV-HIIT: Low-Volume and High-Intensity Interval Training; MICT: Moderate-intensity continuous training; MSWT: Modified Shuttle Walk Test; SD: Standard Deviation; SEE: Standard Error of Estimate; V̇O_2peak: Peak Oxygen Uptake.

KEYWORDS:

• Hypertension
• obesity
• field test
• cardiopulmonary test
• assessment
• exercise design
• sedentary

Acknowledgments

Our special thanks to Javier Pérez-Asenjo and Rodrigo Aispuru for their medical assessment and support, and Exercycle S.L. (BH Fitness Company) for the machines donated to conduct the exercise intervention. Last but not least to all undergraduate students who collaborated in this project (2011-2017 academic years).

Conflicts of interest

None

Additional information

Funding

The Government of the Basque Country (SAIOTEK, SAI12/217) supported the study and to IGA, PC and AMAB with predoctoral grants.