Trends in strength training--United States, 1998-2004.

Strength training is physical activity intended to increase muscle strength and mass. Adults who engage in strength training are less likely to experience loss of muscle mass, functional decline, and fall-related injuries than adults who do not strength train. Studies on strength-training interventions have indicated that inactive older adults who begin regular strength training achieve substantial strength gains within a few months. Because certain health benefits are linked to strength training, a national health objective for 2010 is to increase to 30% the proportion of adults who perform physical activities that enhance and maintain muscular strength and endurance on > or =2 days per week (objective 22-4). This objective is also recommended by the American College of Sports Medicine. CDC analyzed 1998-2004 data from the National Health Interview Survey (NHIS) to determine the annual prevalence of strength training among U.S. adults by age group and race/ethnicity. This report describes the results of that analysis, which demonstrated that although the national prevalence of strength training for U.S. adults increased slightly during 1998-2004, only 21.9% of men and 17.5% of women (age adjusted) in 2004 reported strength training two or more times per week. This is substantially lower than the national 2010 objective of 30% and underscores the need for additional programs to increase strength training among adults.