For a long time, physical activity guidelines were based largely on promoting moderate- to vigorous-intensity aerobic activity (walking, jogging, cycling). Over the last decade, muscle-strengthening exercise has been discovered as not less beneficial for health.
Muscle-strengthening exercise guidelines adopted by the World Health Organization’s (WHO) state that adults over 18 years should have “two or more days per week of muscle-strengthening activity involving major muscle groups.” Such recommendations are due to strong clinical evidence showing that this activity has multiple independent health benefits.
Those benefits include increased skeletal muscle mass/strength, bone mineral density, enhanced ability to perform activities of daily living, and improved cardiometabolic health. They are either independent of or are more effective than, participation in moderate- to vigorous-intensity aerobic activity alone.
Studies conducted between 2004 and 2017 show that between 6.0% and 30.2% of adults (≥18 y) meet muscle-strengthening exercise guidelines (≥2 times/wk). Among nearly 1.8 million US adults, between 2011 and 2017, ∼70% did not meet the guideline.