The ISAR InflEx Trial (Inflammation and Exercise)

A sedentary lifestyle and obesity are associated with chronic low-grade inflammation and an elevated risk of cardiovascular disease (CVD). This study aims to systematically characterize and compare the effects of three distinct exercise modalities - moderate-intensity, vigorous-intensity, and short-duration maximal exercise - each differing in duration and intensity, on systemic inflammation and immune function. The study investigates the potential of exercise as an effective anti-inflammatory intervention for the prevention of CVD.

Adverse lifestyle behaviors, particularly sedentary habits, exacerbate inflammation and maladaptive immune responses, thereby promoting vascular inflammation and the development of atherosclerotic cardiovascular disease. Conversely, adopting healthier behaviors, including regular physical activity, may mitigate these effects, improve overall well-being, and prevent the progression from health to disease. The ISAR InflEx trial aims to systematically evaluate the anti-inflammatory effects of physical exercise on systemic immunity. Healthy volunteers with a BMI of 25.0-30.0 kg/m² who lead a sedentary lifestyle and do not engage in any structured exercise will be enrolled in an exercise intervention. The first group (n = 11 participants) will begin with a two-week period of moderate-intensity exercise, followed by a three-week break. This will be followed by two weeks of vigorous-intensity exercise, again followed by a three-week break, and finally two weeks of short bouts of maximal-intensity exercise. The second and third groups (n = 11 each) will undergo the same procedure but in different sequences, starting with vigorous-intensity exercise and short bouts of maximal-intensity exercise, respectively. Blood samples will be collected before each exercise intervention, midway through the intervention, and after its completion to characterize and compare the systemic immune response. The primary outcome measure will be changes in blood leukocyte counts before and after each intervention. Participants will serve as their own controls, with pre-intervention measurements used as baseline values.

Inclusion Criteria: * BMI 25.0 - 30.0 kg/m² * age 18 - 45 years * informed consent * no regular physical activity (≤1x/week of structured exercise) * willingness to strictly follow and adhere to the intervention protocol for the entire study Exclusion Criteria: * any acute or chronic illness * pregnancy and breastfeeding * active smoking * Regular use of medication