Clinical trial NCT03896828: Practical Approaches for Interrupting Prolonged Sitting to Improve Postprandial Glucose and Protein Metabolism
Official title: Practical Approaches for Interrupting Prolonged Sitting to Improve Postprandial Glucose and Protein Metabolism
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Healthy Adults
Lead sponsor: University of Toronto
Sponsor class: OTHER
First posted: 2019-04-01
Enrollment: 14
Sex: ALL
Minimum age (years): 18
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Fourteen men and women will visit the lab on three separate occasions and will remain seated at a desk all-day (Visit 1) or interrupt this sitting every 30-minutes with either 2-minute walking-breaks (Visit 2) or with 15 body-weight squats (repeatedly rising from a chair and onto tip-toes, Visit 3).
Primary purpose: TREATMENT

Brief summary: The present study will determine the impact of interrupting prolonged sitting with short, 2-minute walks or body-weight squats on: i) postprandial glycemia and insulinemia, and; ii) postprandial utilization of dietary amino acids. We hypothesize that postprandial glycemia and insulinemia will be similarly improved by interrupting prolonged sitting with short walks or body-weight squats, whereas postprandial utilization of dietary amino acids will only be improved by interrupting prolonged sitting with body-weight squats.

Detailed description: Sedentary behavior is an independent risk factor for chronic disease and premature mortality. Despite a growing awareness of the health risks associated with prolonged sitting, Americans spend upwards of 10 hours per day in a sedentary state. Many leisure-time activities and careers of modern society involve prolonged sitting, necessitating an urgent need to identify strategies that mitigate the health consequences of these behaviors. Recent evidence suggests that interrupting prolonged periods of sitting with short breaks of walking or cycling improve postprandial glucose and lipid handling throughout the day. Thus, relatively small quantities of movement represent an efficacious strategy for improving indices of metabolic health. However, more cost-effective and practical interventions that do not require extra space (i.e. walking) or equipment (i.e. cycling or a treadmill desk) beyond one's immediate sedentary space (e.g. office, desk) would help reduce real and/or perceived barriers of adopting this efficacious disease risk-reduction behavior. A currently understudied consequence of prolonged sitting may also be a desensitization of skeletal muscle's ability to use ingested protein, which overtime can result in detriments to the quantity and quality of this important tissue. Body-weight resistance exercise (RE) can augment the body's ability to use ingested protein to support the maintenance of skeletal muscle mass, and therefore may represent a novel exercise mode to minimize consequences of prolonged sitting. The proposed research will be the first to investigate the influence of interrupting prolonged sitting with short breaks of body-weight resistance exercise (RE) on postprandial glucose and protein metabolism. Importantly, the efficacy of this approach will be directly compared to short breaks of walking, which has previously been reported to improve postprandial glycemia in healthy adults.

Eligibility criteria: Inclusion Criteria:

* Men and women between 18-35 yr
* Recreationally active (≤ 150 minutes of moderate-intensity physical activity per week and no more than 3 days/week of exercise)
* VO2peak considered "good" or below based on ACSM age and sex normative values
* Experiencing regular menstrual periods and not taking hormonal oral contraceptives (females only)

Exclusion Criteria:

* Inability to perform physical activity as determined by the PAR-Q
* Inability to adhere to protocol guidelines (e.g. alcohol, standardized diet)
* Physical limitations for walking or repeatedly rising from a chair
* Regular tobacco use
* Illicit drug use (e.g. growth hormone, testosterone)
* Hormonal oral contraceptive use (females only)
* Diagnosed medical condition under the care of a physician (e.g. type 2 diabetes)

Primary outcomes:
measure: Postprandial insulin area under the curve (AUC) to breakfast and lunch
timeFrame: 3 hours postprandial
Secondary outcomes:
measure: Postprandial glucose area under the curve (AUC) to breakfast and lunch
timeFrame: 3 hours postprandial
measure: Skeletal muscle dietary protein incorporation
timeFrame: 7.5 hours postprandial
Other outcomes:
Locations:
city: Toronto
country: Canada
facility: Goldring Center for High Performance Sport
state: Ontario
Study officials:
affiliation: University of Toronto
name: Daniel Moore, Ph.D
role: PRINCIPAL_INVESTIGATOR
References: