Exercise Intensity and Postprandial Effects of Breaking Sedentary Behavior in Overweight Adults

Official title

Postprandial Cardiometabolic Effects of Interrupting Sedentary Behavior With Exercise of Varying Intensity in Healthy Overweight Adults

Overview

The purpose of this study is twofold: (1) to determine whether breaking up prolonged sitting with aerobic or sprint cycling breaks reduces postprandial blood glucose, insulin, CRP, and blood pressure, which are established risk markers for cardiometabolic diseases; and (2) to assess substrate oxidation during this period in order to identify which exercise condition promotes the greatest increase in fat oxidation.

Detailed description

Sedentary behavior (SED) refers to activities such as sitting, lying down, or reclining that require energy expenditure of ≤1.5 MET during the time spent awake. Prolonged and continuous sedentary behavior leads to adverse effects such as abnormal postprandial metabolic responses, insulin resistance, vascular dysfunction, high blood pressure, increased carbohydrate oxidation, and inflammation. Epidemiological data also show that SED increases the risk of mortality, cardiovascular disease, type 2 diabetes, and certain types of cancer. Experimental studies have shown that 2-5 minutes of low- or moderate-intensity aerobic exercise performed every 20-30 minutes during the postprandial period improves cardiometabolic health by reducing glucose, insulin, and blood pressure during the postprandial period. On the other hand, it is known that short-term sprint interval exercise (SIE) increases insulin sensitivity by rapidly depleting muscle glycogen, improves glucose control, lowers blood pressure, and increases fat oxidation. With these effects, SIE may be a time-efficient method for interrupting SED. Although the cardiometabolic benefits of SIE and aerobic exercise interruptions (AEI) are known, there is a lack of studies comparing the effects of interrupting SED with these two exercise types of different intensities in preventing postprandial cardiometabolic dysfunction. In this context, the aim of the study is to compare the postprandial cardiometabolic effects of interrupting sedentary behavior with AIE and sprint exercise interruptions (SEI) in overweight but otherwise healthy women and men aged 35-45. In this randomized crossover trial, volunteers will participate in three trials: 1) AEI, 2) SEI, and 3) SED. There will be a minimum 3-day washout period between trials. In the SEI and AEI trials, exercise interruptions will be implemented every 30 minutes during the 7-hour sitting period, whereas in the SED trial, participants will remain seated continuously for the entire duration. In all conditions, two meals (breakfast and lunch) will be served 3 hours apart, and the trials will begin, after the breakfast meal is consumed. Venous blood samples taken hourly during the experiment will be used to analyze insulin, glucose, and C-reactive protein (CRP) levels. In addition, blood pressure will be measured hourly, and fat oxidation will be assessed at the baseline, 2nd, 5th, and 7th hours. The effects of the conditions on glucose and insulin will be evaluated using linear mixed models. A Two-Way (Trial x Number of Repeats) Analysis of Variance for Repeated Measures will be used to detect differences between conditions.

Interventions

• Other Aerobic Exercise Intervention
  In the aerobic exercise condition, participants will perform 2 minutes of moderate-intensity continuous cycling.
• Other Sprint Exercise Intervention
  In the sprint condition, participants will complete a 10-second all-out sprint, as determined during the preliminary test.
• Other Sedentary Behaviour Intervention
  Participants will remain seated for a total duration of 7 hours. During this period, they will be instructed to minimize excessive movement and will only be permitted to rise from the chair for voiding purposes.

Primary outcome measures

• Insulin [Time frame: 7 hour for each experimental condition]

Secondary outcome measures (4)

• Glucose [Time frame: 7 hour for each experimental condition]
• CRP [Time frame: 7 hour]
• Substrate oxidation [Time frame: 0, 2th, 5th, 7th hours]
• Blood pressure [Time frame: 7 hour]

Eligibility criteria

Inclusion criteria

• Being physically inactive (not doing at least 150 minutes/week of structured exercise).
• Having a physical activity level of <5000 steps/day.
• Having a BMI between 25 and 29.9 kg/m2.
• Having a history of regular menstrual cycles for female participants.
• Having medical examination approval.

Exclusion criteria

• Taking any acute or chronic medication or supplement that may affect metabolism.
• Having an acute or chronic illness that limits exercise (musculoskeletal problems, cardiovascular disorders, respiratory problems, etc.).
• Consuming tobacco products.
• Meeting 3 or more of the metabolic syndrome criteria (waist circumference of 102 cm or more in men, 88 cm or more in women, triglyceride level of 150 mg/dL or higher, HDL cholesterol level below 40 mg/dL in men and 50 mg/dL in women, blood pressure of 130/85 mmHg or higher, fasting blood glucose level of 100 mg/dL (5.6 mg/L) or higher).

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Crossover

Masking

Open label

Primary purpose

Prevention

Study locations

Turkey (Türkiye) · 1 center

• Hacettepe Sports Science Faculty, Hacettepe Beytepe Clinic — Ankara

Publications

• Compher C, Frankenfield D, Keim N, Roth-Yousey L; Evidence Analysis Working Group. Best practice methods to apply to measurement of resting metabolic rate in adults: a systematic review. J Am Diet Assoc. 2006 Jun;106(6):881-903. doi: 10.1016/j.jada.2006.02.009. PMID 16720129
• Frayn KN. Calculation of substrate oxidation rates in vivo from gaseous exchange. J Appl Physiol Respir Environ Exerc Physiol. 1983 Aug;55(2):628-34. doi: 10.1152/jappl.1983.55.2.628. PMID 6618956
• DeMers D, Wachs D. Physiology, Mean Arterial Pressure. 2023 Apr 10. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from http://www.ncbi.nlm.nih.gov/books/NBK538226/ PMID 30855814
• Stergiou GS, Palatini P, Parati G, O'Brien E, Januszewicz A, Lurbe E, Persu A, Mancia G, Kreutz R; European Society of Hypertension Council and the European Society of Hypertension Working Group on Blood Pressure Monitoring and Cardiovascular Variability. 2021 European Society of Hypertension practice guidelines for office and out-of-office blood pressure measurement. J Hypertens. 2021 Jul 1;39(7) PMID 33710173
• Mattes RD, Campbell WW. Effects of food form and timing of ingestion on appetite and energy intake in lean young adults and in young adults with obesity. J Am Diet Assoc. 2009 Mar;109(3):430-7. doi: 10.1016/j.jada.2008.11.031. PMID 19248858
• Augustin LSA, Kendall CWC, Jenkins DJA, Willett WC, Astrup A, Barclay AW, Bjorck I, Brand-Miller JC, Brighenti F, Buyken AE, Ceriello A, La Vecchia C, Livesey G, Liu S, Riccardi G, Rizkalla SW, Sievenpiper JL, Trichopoulou A, Wolever TMS, Baer-Sinnott S, Poli A. Glycemic index, glycemic load and glycemic response: An International Scientific Consensus Summit from the International Carbohydrate Qua PMID 26160327
• Diet, nutrition and the prevention of chronic diseases. World Health Organ Tech Rep Ser. 2003;916:i-viii, 1-149, backcover. PMID 12768890
• Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990 Feb;51(2):241-7. doi: 10.1093/ajcn/51.2.241. PMID 2305711

Identifiers

NCT: NCT07229963 · SBA 25/679

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗