An interventional study of Aerobic Exercise Intervention and Sprint Exercise Intervention in Cardiovascular Risk Markers, Postprandial Metabolism and Exercise Physiology, sponsored by Hacettepe University. Recruiting at 1 site in Turkey (Türkiye). Open to participants aged 30 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-24.
Sponsored by Hacettepe University · Not applicable, Interventional, and Prevention
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.
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 30-45. In this randomized crossover trial, volunteers will participate in three trials: 1) AEI, 2) SEI, and 3) SED. There will be a minimum 4-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 for every 30 minutes of the first two hours following meals to measure glucose and to be taken hourly during the rest 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.
1,273 studies on the registry are indexed under Sedentary Behavior; 300 are open to participants now.
This study's planned enrollment of 18 is below the median of 60 across 1,076 interventional studies indexed under Sedentary Behavior.
Browse Sedentary Behavior studies →Hacettepe University is the lead sponsor of 1,007 studies on the registry; 214 are open to participants now.
Compared within Sedentary Behavior, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Motor Activity. The counts are of registry records indexed under each term, refreshed daily. How we classify →
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The sedentary condition will take place in a seated position. During the seated condition, volunteers will be seated at a typical desk chair at an appropriate height with hip and knee angles of \~90° and feet flat on the floor. The seating area will include a standard desk chair, a work desk, and the volunteers' personal laptops. Volunteers will be instructed prior to the visit to avoid behaviors such as fidgeting, excessive leg movements, and crossing their legs to minimize potential extraneous effects.
Other: Sedentary Behaviour Intervention
The protocol that will interrupt sitting with AEI will involve cycle exercises performed at 50% of Wattmax for 2 minutes. The W and rpm levels corresponding to 50% of Wattmax will be determined using the values recorded during the determination of Wattmax.
Other: Aerobic Exercise Intervention
The protocol that will interrupt sitting with SEI will involve cycle exercises performed at the maximum revolutions per minute achievable within 10 seconds. Immediately (2-3 seconds) before each SEI, volunteers will increase their pedal cadence to the maximum speed they can achieve, after which a pedal load will be applied to the bicycle ergometer and a sprint will be performed against the applied load for 10 seconds. During each sprint, the pedal load will be applied at %200 Wattmax level.
Other: Sprint Exercise Intervention
In the aerobic exercise condition, participants will perform 2 minutes of moderate-intensity (%50 Wattmax) continuous cycling.
In the sprint condition, participants will complete a 10-second sprint at %200 Wattmax level, as determined during the preliminary test.
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.
Insulin
Postprandial insulin. Net incremental area under the curve and total area under the curve for each 7 h condition will be calculated for insulin.
Time frame: 7 hour for each experimental condition
Glucose
Postprandial glucose. Net incremental area under the curve and total area under the curve for each 7 hour condition will be calculated for glucose.
Time frame: 7 hour for each experimental condition
CRP
Postprandial CRP. Net incremental area under the curve and total area under the curve for each 7 h condition will be calculated for CRP.
Time frame: 7 hour
Substrate oxidation
Postprandial substrate oxidation. During each experimental visit, for 7 hours, volunteers' respiratory data will be collected using a direct calorimeter with canopy hood in lying position for 10 minutes at 0, 2th, 5th, and 7th hours. The volunteers' resting fat and carbohydrate oxidations will be determined from the obtained data.
Time frame: 0, 2th, 5th, 7th hours
Blood pressure
Postprandial arterial blood pressure will be measured hourly for 7 h using an automatic blood pressure monitor with a cuff of appropriate size. The systolic and diastolic BP values measured will be recorded, and the mean arterial pressure will be calculated.
Time frame: 7 hour
Plan to share: No — We do not plan to share IPD with other researchers due to privacy concerns and ethical restrictions outlined in the study's informed consent procedure.
Started Sep 2026 (actual). Primary completion is estimated for Nov 2026, 2 months after the start.
Of 733 non-industry interventional studies with no phase under Sedentary Behavior, half reached primary completion within 14 months of starting (the median), counting those still running; a quarter within 6 and three quarters within 31. This study's planned 2 months is below that.
Counting every sponsor, half of 741 studies reached it within 14 months; a quarter within 6 and three quarters within 31.
How these figures are worked out, and which studies are left out of them.
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