Effects of Interrupting Sedentary Behavior With High - or Low Intensity PA on CVD - and Cardiometabolic Riskfactors, and Cognitive Performance.

NCT ID: NCT05709379

Last Updated: 2026-01-21

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 25 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-01-02
• Study Completion Date: 2025-12-20

Brief Summary

The knowledge gap on sedentary behavior and sedentary breaks includes whether detrimental effects of sedentary behavior can be fully attenuated by 1.) sedentary breaks 2.) physical activity or 3.) both combined. Specifically, when breaking sedentary time which physical activity pattern- and intensity modifies the negative effects of sedentary behavior on glucose- and lipid metabolism? This lack of quantitative evidence calls for prospective experimental studies investigating the physiological and biological impacts of sedentary behavior, as well as the effectiveness of different strategies to reduce sedentary time. Thus, quantifying effects of the intensity, frequency, volume of sedentary breaks and/or physical activity on predefined outcomes is of importance.

Aims:

Our primary aims are to investigate the effects of breaking up sedentary time on glucose- and lipid metabolism and thus examine whether physical activity intensity breaks during sedentary breaks matter. Specifically, the aims of the PhD-project are to provide knowledge on the following questions:

• How does high- or low physical activity intensity sedentary breaks acutely influence glucose- and lipid metabolism under iso-caloric conditions?

Detailed Description

The participants will undergo 3 different trial conditions of which all are iso-caloric, but with different intensities when executing physical activity (PA) by treadmill walking corresponding to 25-30% or 80-85%, respectively, of their individual VO2max/peak values. PA intensities are estimated from the individual's pre-test. The trial-conditions are iso-caloric, and tailored to each individual's energy expenditure. This study has a is randomized cross-over design. If found eligible from step 1 and 2 in the inclusion process, participants will be invited to a final screening day in our lab. Eligible participants then consenting to joining the study will continue on to 3 trial days. Due to possible acute rise in insulin for up to 48 hours, a 5-14 day washout period between trials will be used to avoid carryover effects. In the washout periods between experimental conditions the participants will resume their habitual life activities and behaviors, i.e., diet and physical activity patterns. However, from visit 2, during washout the participants will wear accelerometers (ActiGraph GTX3+, Pensacola, FL) during waking hours to objectively measure sedentary time and physical activity for 7 consecutive days after each trial. Average sedentary time (hour/day) and time spent in , light-, moderate- and vigorous physical activity intensity (min/day) will be derived. During the main trial days, the participants may read or work on a personal computer during the sedentary time in the respective trial conditions. The sample size calculations with glucose as the primary outcome, are based on the study by Dunstan et al. (2012). They estimated that 19 paired observations were needed to secure a power of 0.90 in order to detect the smallest expected effect size between the interventions, when using a two-tailed test with a significance level of 5%. To account for the possibility of dropouts the sample size in the present project is set to recruit 30 participants, with 25 participants completing the trials, and thus planning for 80% power

Conditions

Sedentary Behavior; Physical Activity

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: DOUBLE

Study Groups

Control trial

Sitting from 8 am until 3pm.

Group Type: EXPERIMENTAL

Sedentary behavior

Intervention Type: BEHAVIORAL

Interrupting sitting with walking/jogging at either high -or low physical activity intensity.

High intensity sedentary breaks

Physical activity on 80-85% of individual VO2max every hour. Modality: Hill walking/jogging on treadmill.

Group Type: EXPERIMENTAL

Sedentary behavior

Intervention Type: BEHAVIORAL

Interrupting sitting with walking/jogging at either high -or low physical activity intensity.

Low intensity sedentary breaks

Physical activity on 25-30% of individual VO2max every hour. Modality: Hill walking on treadmill.

Group Type: EXPERIMENTAL

Sedentary behavior

Intervention Type: BEHAVIORAL

Interrupting sitting with walking/jogging at either high -or low physical activity intensity.

Interventions

Sedentary behavior

Interrupting sitting with walking/jogging at either high -or low physical activity intensity.

Intervention Type: BEHAVIORAL

Eligibility Criteria

Inclusion Criteria

• Predominantly sedentary occupation.
• Physical activity: equal or less tham 150 minutes /week
• Nonobese. Central adiposity: Waist circumference equal or less than 102 cm for men and equal or less than < 88 cm for women. BMI < 30 km·m2

Exclusion Criteria

• Shift-work
• Smoking
• Pregnancy
• Current use of medication, except from hormonal contraceptives.
• No presence of any co-morbidity (e.g. diabetes type 2, cardiovascular or cardiorespiratory disease, or other conditions known to affect carbohydrate and lipid metabolism - thyroid-, -liver or kidney).
• Systolic /diastolic resting blood pressure: > 140/90 mmHg
• Fasting blood glucose concentration: > 6.1 mmol/L
• Abnormal total cholesterol, LDL, LDL or triglyceride concentrations (> 50% above recommendations)

• Minimum Eligible Age: 20 Years
• Maximum Eligible Age: 45 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

The Research Council of Norway

OTHER

Sponsor Role: collaborator

Norwegian School of Sport Sciences

OTHER

Sponsor Role: lead

Responsible Party

Jostein Steene-Johannessen

Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Jostein Steene-Johennessen, Professor

Role: PRINCIPAL_INVESTIGATOR

Norwegian School of Sports Sciences

Locations

Norwegian School of Sports Sciences

Oslo, Oslo County, Norway

Countries

Norway

Other Identifiers

GENSED#2

Identifier Type: -

Identifier Source: org_study_id