High Intensity Interval Exercise VS Moderate Intensity, Continuous Training

Cardiovascular exercise (CV), and other such classifications of fitness endeavors, has extensive research to support the American College of Sports Medicine’s broad definition as “exercise medicine.” Current, established activity guidelines include recommending a minimum of 150 minutes of moderate-intensity exercise, or 75 minutes of high-intensity weekly exercise to maintain or improve cardiorespiratory fitness and health, while reducing the risk to non-communicable diseases – type 2 diabetes, cancer, osteoporosis, stroke, and more. The nomenclature of CV exercise has specific variations, such as endurance exercise, in the form of moderate-intensity, continuous training (MICT), and high-intensity interval exercise (HIIE) – referenced as high-intensity interval training (HIIT), and sprint interval training (SIT).

HIIT involves alternating intervals at greater than 80% of maximum endurance capacity (VO2 Max) or 85% of your maximal heart rate (220-age), typically 1 to 4 minutes in duration – with lower intensity, active or passive recovery, while SIT uses short – full go – intervals, typically less than 30 seconds, with short, passive recovery.

Writing in the March 2021 issue of Medicine & Science in Sports & Exercise – Effectiveness of HIIE versus MICT in Improving Cardiometabolic Risk Factors in Health and Disease: a Meta-Analysis – researchers from the Sports Medicine Department, Clinical Epidemiology and Applied Biometrics Department, and the Psychosomatic Medicine and Psychotherapy Department, University Hospital of Tubingen in Germany, used a meta-analysis (many similar studies) to investigate the clinical benefits distinguishing each exercise modality (HIIE and MICT) in health and disease.

The data search began in January of 2018 and culminated in July of 2020.
The seven key clinical endpoints of the literature analysis included: “physical fitness (VO2 max), endothelial function (flow-mediated dilation [FMD]), body composition (body mass index [BMI], body mass, and body fat), blood pressure (systolic and diastolic blood pressure), blood lipids (HDL, LDL, triglycerides, and total cholesterol), inflammation (C-reactive protein [CRP]), and insulin and glucose metabolism (fasting glucose, fasting insulin, glycated hemoglobin [HbA1c], and insulin resistance (HOMA-IR).”
After a comprehensive analysis of the data, the researchers said, “overall, HIIE showed to be more effective in improving cardiovascular health and cardio- respiratory fitness, whereas MICT was superior in improving long-term glucose metabolism.

From an aging perspective, the data analysis determined that relative to endothelial function, which protects tissues from toxic substances, regulates the blood clotting mechanism, controls the transition of fluid and certain substances between the blood and tissues, and inflammatory control in tissues – it was determined that the HIIE had higher effects than did the MICT – the result of the “interval-like” exercise training programs inducing a, “higher shear stress, promoting an increased nitric oxide release.”

The Germans recommended that, “in the process of personalized training counseling, health-enhancing effects of exercise training may be improved by considering the individual risk profiles.”

And, that risk stratification needs to start with your personal physician. For more information on this topic and more, Check out Our  Open Access Research  page at the bottom of the Home Screen!