Author Interviews, Brigham & Women's - Harvard, Exercise - Fitness, JAMA / 02.06.2019 Interview with: I-Min Lee, MD, ScD Professor of Medicine, Harvard Medical School Professor of Epidemiology Harvard T.H. Chan School of Public Health What is the background for this study? Response: While we have many studies showing that physical activity is beneficial for health, there are few data on steps and health, particularly long-term health outcomes.  An expert committee – the 2018 Physical Activity Guidelines Advisory Committee, which reviewed the scientific evidence to support the recently released Physical Activity Guidelines for Americans, 2nd edition – noted this (i.e., the relation between steps and health outcomes) to be a critical gap in knowledge, since many individuals are using wearables and monitoring their step counts. We often hear the number 10,000 steps cited as a daily goal, but the basis for this number is unclear. It likely originated as a marketing tool: in 1965, the Yamasa Clock and Instrument Company, Japan sold a pedometer called “Manpo-kei” – “ten thousand steps meter” in Japanese. For many older people, 10,000 steps/day can be a very daunting goal; thus, we wanted to investigate whether this was necessary for lower mortality rates in older women.  Additionally, steps taken can be fast or slow, and there are no published studies on step intensity and long-term health outcomes.  Note that walking pace and step intensity are not the same concept: walking pace gauges intensity when walking purposefully (e.g., for exercise or transportation), while step intensity assesses an overall best natural effort in our daily life. (more…)