Cardiometabolic Effects of Combined Aerobic Exercise and Non-Exercise Physical Activity

According to objective and subjective measurements, time spent sedentary varies between 2.5 hours and 10 hours approximately in European countries. In America, this time is 8.44 hours on average. According to accelerometer data, the average total sedentary time of university students is 9.82 hours per day. Sedentary behaviour (SB) is associated with cardiometabolic risk markers and increased risk of cardiovascular disease, independent of moderate and vigorous physical activity (PA). Replacing sedentary time with PA of any intensity, including low-intensity, reduces all-cause mortality.

In terms of some cardiovascular risk variables (e.g., high triglycerides, glucose, LDL cholesterol, total cholesterol), data are insufficient and conflicting on the superiority of increasing non-exercise PA in addition to aerobic exercise over aerobic exercise alone. Additionally, to our knowledge, whether increasing non-exercise PA combined with aerobic exercise is superior to performing aerobic exercise alone in young overweight women with high sedentary time has not been investigated. Therefore, this study was planned to investigate whether reducing SB and increasing non-exercise PA combined with aerobic exercise in overweight young women between the ages of 18-35 is superior to performing aerobic exercise alone in terms of some cardiometabolic variables. For this purpose, overweight female individuals between the ages of 18-35 will be invited to the research. Thirty-two female volunteers who meet the inclusion and exclusion criteria will be randomly assigned to two different groups of this research. These groups will be as follows:

Aerobic Exercise Group: Participants in this group will do moderate-intensity aerobic training four days a week for 8 weeks.

Aerobic Exercise+non-Exercise Physical Activity Group: Participants in this group will reduce their sedentary time and increase non-exercise PA in addition to moderate-intensity aerobic training for four days a week for 8 weeks.

PA and SB data of the participants in both groups will be monitored with a wrist worn accelerometer throughout the study. At the beginning of the study, 4 weeks after the beginning and at the end of 8 weeks, participants will be evaluated in terms of the cardiometabolic variables. These variables are fasting serum glucose, triglyceride, HDL cholesterol, LDL cholesterol, HbA1c, systolic blood pressure, diastolic blood pressure, cardiorespiratory fitness, body mass index, waist and hip circumference, and body fat percentage. If there is a difference between the two group averages in terms of all variables and the group-time interactions test assumptions are met, analysis will be made with two-way mixed analysis of variance (ANOVA). Since 3 measurements will be made over time, pairwise differences in change over time will be analyzed with a post hoc Bonferroni test.

Inclusion criteria

• To have a body mass index between 25 kg.(m2)-1 and 29.9 kg.(m2)-1
• Self reported sitting time greater than 7 hours per day
• Not exercising regularly in the last 3 months

Exclusion criteria

• Hypertension
• Coronary heart disease
• Heart failure
• Diabetes mellitus (A1C being 6.5% and above)
• Prediabetes (A1C between 5.7% and 6.4%)
• Metabolic syndrome
• Hypothyroidism
• Non-alcoholic fatty liver disease
• Chronic inflammatory disease
• Chronic renal failure
• Cushing's syndrome
• Musculoskeletal disorder that will affect the ability to do physical activity
• HIV infection
• Being on antihypertensive medication
• Being on lipid-lowering medication
• Being on antidiabetic medication
• Being on systemic glucocorticoid medication
• Smoking
• Pregnancy