Type 2 diabetes is a metabolic disorder characterized by skeletal muscle insulin resistance. High-intensity interval training (HIIT) improves skeletal muscle insulin sensitivity, but the demanding nature of traditional HIIT sessions can be daunting for people unaccustomed to regular physical activity. A 2012 study found that reduced-exertion high-intensity interval training (REHIT) improved aerobic capacity and metabolic health in people who were sedentary – a risk factor for developing type 2 diabetes.

The study involved 29 sedentary young adults. Half the participants engaged in three 10-minute REHIT sessions weekly for six weeks. Each session consisted of low-intensity cycling and one or two brief “all-out” sprints lasting between 10 and 20 seconds. The other half of the participants remained sedentary. Researchers assessed the participant’s aerobic capacity (measured as VO2 peak) and insulin sensitivity before and after their respective interventions.

Ten of the 15 REHIT participants completed all 18 sessions, indicating high compliance. Aerobic capacity increased by 15 percent in males and 12 percent in females. Insulin sensitivity improved by 28 percent in males but not in females. Participants rated their perceived exertion as “hard” or “somewhat hard.”

Encouraging regular, balanced exercise that includes cardiorespiratory, strength, and flexibility training can optimize health benefits. However, addressing barriers, such as lack of time or access to formal exercise equipment, is crucial to have widespread effects. The findings in this small study suggest that brief, reduced-exertion high-intensity training improves aerobic capacity and metabolic health in sedentary people despite a low time commitment (just 30 minutes per week) and relatively low effort. Learn more about REHIT and how it differs from HIIT and SIT in this clip featuring Dr. Martin Gibala.

• Read study abstract.