Effect of a 1-year intervention comprising brief counselling sessions and low-dose physical activity recommendations in Japanese adults, and retention of the effect at 2 years: a randomized trial

Abstract

Background: In an effort to increase people's adherence to active lifestyles, contemporary physical activity (PA) guidelines now include low-dose PA.

Methods: PA was evaluated in 583 participants of the Nutritional and Physical Activity Intervention Study (NEXIS) cohort (30-65 years old); 349 inactive participants (MVPA, 2.7 ± 1.0 MET-h/day) were randomly assigned to the intervention or control groups, and 235 active participants participated in follow-up visits. The intervention aimed to increase MVPA and comprised five brief counseling sessions over 1 year. The 1-year target for the participant was increasing their step-count to 10,000 steps/d or +3000 steps/d, relative to the baseline score. The counseling sessions were designed to stimulate progressive changes in physical behaviors by recommendations promoting small and/or light-intensity bouts of PA. PA was measured at baseline, the end of the intervention, and 1 year after the intervention ended. Additionally, several nutrition, health, and fitness parameters were measured.

Results: Participants in the intervention group significantly increased their step-count from 8415 ± 1924 at baseline to 9493 ± 2575 at the end of the 1-year period. During the same period, MVPA significantly increased by 0.9 MET-h. The daily time spent in ≥ 3, ≥ 4 and ≥ 5 MET activities increased by 11, 6, and 3 min, respectively. This increase in PA remained observable 1 year after intervention concluded. The active group maintained higher physical activity levels throughout the two years. The intervention group showed smaller energy intakes at the end of the 2-year period. Significant correlations were noted between the 1-year change in MVPA and the change in resting heart rate (r = - 0.22), and between the 2-year change in MVPA and the change in waist circumference (r = - 0.08) and peak oxygen consumption capacity (r = 0.23) in the intervention group only.

Conclusions: A prolonged and progressive PA intervention promoting small bouts of light-to-moderate PA may be used in healthy, not-optimally-active people to increase PA beyond the strict period of the intervention. Further studies are necessary to understand whether low-dose PA messages can be effective in initiating a progressive increase toward larger amounts of PA.

Trial registration: Clinical Trials.gov, NCT00926744, retrospectively registered.

Keywords: Accelerometer monitor; Cohort study; Counseling; Health promotion; Moderate-to-vigorous physical activity; Physical activity; Randomized control trial; Step-count.

Conflict of interest statement

YG, MI, RK, HK, KK, MM, NM, AM, HM, HO, KS, NT, MT, KT, JT, and KY declare that they have no competing interests.

© 2021. The Author(s).

Figures

Fig. 1

CONSORT flow chart of the study. 1Sample size counted in 2015. 2Five-hundred-eighty-three of the 851 participants primarily assigned to the intervention, control, or active groups renewed their consent in 2019, granting access to the data for an additional 5-year period. 3PA assessment may have been corrupted for the following reasons: medical conditions impairing normal physical behaviors during the assessment period (pregnancy, injury, etc.), acceleration signal summary not meeting inclusion criteria (4 days with a minimum of 10 h/d wearing time) despite several measurement attempts, etc. 4The number of analyzed data varies for each variable (see N values within brackets for each group). Reasons for missing data include: baseline assessment of physical activity not meeting quality standards, non-eligibility to physical fitness tests (e.g., participant becoming over 65 during the course of the study), impossible extraction of some specific parameters (e.g., vascular echo parameters due to the quality of images), participant not willing/able to perform one specific test on the date of the visit, among others

Fig. 2

Structure of the PA intervention and flow of the information between the counseling sessions. The four components of the intervention are boldfaced and underlined

Fig. 3

Moderate-to-vigorous physical activity in the active, control, and intervention groups over 3 years. The average value is indicated with a diamond mark (+ text) in each box. MVPA, moderate-to-vigorous physical activity. *Different from the two other groups. ‡Different from the control group. ¥Different from the baseline