Estimation methods to detect changes in cardiorespiratory fitness due to exercise training and subsequent detraining

Tomoaki Matsuo; Rina So; Fumiko Murai

doi:10.1007/s00421-022-05113-z

Estimation methods to detect changes in cardiorespiratory fitness due to exercise training and subsequent detraining

Eur J Appl Physiol. 2023 Apr;123(4):877-889. doi: 10.1007/s00421-022-05113-z. Epub 2022 Dec 23.

Authors

Tomoaki Matsuo^{1

2}, Rina So^{3

4}, Fumiko Murai⁴

Affiliations

¹ Ergonomics Research Group, National Institute of Occupational Safety and Health, Japan, Kawasaki, Japan. matsuo@h.jniosh.johas.go.jp.
² Research Center for Overwork-Related Disorders, National Institute of Occupational Safety and Health, Japan, Kawasaki, Japan. matsuo@h.jniosh.johas.go.jp.
³ Ergonomics Research Group, National Institute of Occupational Safety and Health, Japan, Kawasaki, Japan.
⁴ Research Center for Overwork-Related Disorders, National Institute of Occupational Safety and Health, Japan, Kawasaki, Japan.

PMID: 36550384
DOI: 10.1007/s00421-022-05113-z

Abstract

Purpose: To determine whether estimated maximal oxygen consumption ([Formula: see text]) can detect cardiorespiratory fitness (CRF) changes by behavioral modifications. This study compared changes in measured [Formula: see text]O_2max (m[Formula: see text]O_2max) through exercise intervention with e[Formula: see text]O_2max using a multiple regression model (MRM) and linear extrapolation method (LEM).

Methods: A cross-sectional analysis involving 173 adults was conducted to establish an MRM by including age, sex, body mass index, questionnaire score, heart rate (HR) from step test, and m[Formula: see text]O_2max. Subsequently, 15 men participated in an intervention experiment comprising an 8-week, high-intensity interval training, followed by 8-week detraining, and completed anthropometric measurements, questionnaires, step tests, and m[Formula: see text]O_2max tests. m[Formula: see text]O_2max changes throughout the intervention were compared to e[Formula: see text]O_2max changes calculated using the MRM and LEM. The LEM used the HR during the step test with constant values (predetermined [Formula: see text]O₂), such as the Chester step test.

Results: Inclusion of the step test HR in a questionnaire-based MRM improved the estimation power, although the MRM underestimated higher m[Formula: see text]O_2max values. In the intervention, m[Formula: see text]O_2max increased by 20.0 ± 14.1% (P < 0.01) and subsequently decreased by 9.5 ± 6.6% (P < 0.01) after exercise training and detraining, respectively. Significant method × time interactions were observed between m[Formula: see text]O_2max and e[Formula: see text]O_2max in the MRM but not in the LEM, i.e., an apparent systematic error (underestimation of high values) of the MRM was absent in the LEM, although the correlation between m[Formula: see text]O_2max and e[Formula: see text]O_2max using the LEM was moderate.

Conclusion: e[Formula: see text]O_2max, particularly using the MRM with HR as an explanatory factor, is not an appropriate method for detecting CRF changes along with behavioral modifications.

Clinical trial registration: Registered number, UMIN000041031; Registered date, 2020/07/08; URL, https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000046855.

Keywords: Cardiorespiratory fitness; Chester step test; High-intensity interval training; Multiple regression analysis.

MeSH terms

Adult
Cardiorespiratory Fitness*
Cross-Sectional Studies
Exercise
Exercise Test
Humans
Male
Oxygen Consumption

Grants and funding

N-P02-02/National Institute of Occupational Safety and Health, Japan