Effects of Interrupting Sedentary Behavior With High - or Low Intensity Physical Activity on Cardiovascular - and Cardiometabolic Riskfactors, and Cognitive Performance.
概览
- 阶段
- 不适用
- 干预措施
- 未指定
- 疾病 / 适应症
- Sedentary Behavior
- 发起方
- Norwegian School of Sport Sciences
- 入组人数
- 25
- 试验地点
- 1
- 主要终点
- Total (tAUC)- and incremental areas under the curve (iAUC) for glucose
- 状态
- 已完成
- 最后更新
- 3个月前
概览
简要总结
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?
详细描述
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
研究者
Jostein Steene-Johannessen
Professor
Norwegian School of Sport Sciences
入排标准
入选标准
- •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
排除标准
- •Shift-work
- •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)
结局指标
主要结局
Total (tAUC)- and incremental areas under the curve (iAUC) for glucose
时间窗: The iAUC for glucose will be assessed during the procedure and consist of measures every 30 minute throughout the trial (420 minutes)
During each of the trial conditions blood samples will be taken in the fasted state in the morning and then every 30 minutes of the trials (total 420minutes) through a peripheral venous catheter. We will then calculate the iAUC for glucose for each of the trial condition and compare the different trial conditions with the control condition
次要结局
- tAUC and iAUC analyses for insulin(The iAUC for the secondary outcomes will be assessed during the procedure and consist of measures every 30 minute throughout the trial (420 minutes))
- tAUC and iAUC analyses for triglycerides(The iAUC for the secondary outcomes will be assessed during the procedure and consist of measures every 30 minute throughout the trial (420 minutes))
- tAUC and iAUC analyses for lipids(The iAUC for the secondary outcomes will be assessed during the procedure and consist of measures every 30 minute throughout the trial (420 minutes))
- tAUC and iAUC analyses for c-peptide(The iAUC for the secondary outcomes will be assessed during the procedure and consist of measures every 30 minute throughout the trial (420 minutes))
- Cognitive function and performance(The cognitive measures will be performed during the procedure (at approx 400 minutes))