Dose–response association of aerobic and muscle-strengthening physical activity with mortality: a national cohort study of 416 420 US adults

Correspondence to Dr C Arden Pope, Department of Economics, Brigham Young University, Provo, UT 84602, USA; [email protected]

WHAT IS ALREADY KNOWN ON THIS TOPIC

• To optimise health, the US Department of Health and Human Services recommends ≥2.5–5 hours/week of moderate-intensity aerobic physical activity (MPA), 1.25–2.5 hours/week of vigorous-intensity aerobic physical activity (VPA) or an equivalent combination of the two, in addition to ≥2 times/week of muscle-strengthening exercise (MSE).

WHAT THIS STUDY ADDS

• Using a nationally representative, prospective cohort study of 416 420 US adults, we identified the dose–response association and minimum effective doses of aerobic physical activity (PA) and MSE necessary to result in clinically significant lower all-cause mortality risk.

• Total aerobic physical activity (MPA+VPA) durations of 3 hours/week and MSE completed ~1–2 times/week is sufficient to substantively reduce the risk of all-cause mortality. MSE completed in combination with aerobic PA confers additional mortality risk reduction beyond aerobic PA alone.

• There is minimal evidence of additional mortality risk reduction beyond 3 hours/week of aerobic PA or 2 times/week of MSE.

HOW MIGHT IT IMPACT CLINICAL PRACTICE IN THE FUTURE

• US healthcare providers may inform adults that they may substantially reduce their risk of mortality by performing about 3 hours/week of aerobic PA at their preferred intensity-level and 1–2 times/week of MSE targeting all major muscle groups.

Introduction

Regular physical activity (PA) participation lowers non-communicable disease incidence (eg, cardiovascular disease, type 2 diabetes) and confers several other physiological and psychosocial health benefits.^1–3 The WHO recommends adults accumulate ≥150 min/week of moderate-intensity aerobic PA (MPA), 75 min/week of vigorous-intensity aerobic PA (VPA) or an equivalent combination of the two.³ Despite the known health benefits, >1.4 billion adults do not meet these recommendations.⁴ Physical inactivity is thus a major public health concern,⁵ with the WHO ranking physical inactivity as the fourth leading risk factor for mortality over the past decade.⁶ Indeed, annual physical inactivity-related deaths and healthcare costs exceed 5 million¹ and $67.5 billion,^{7 8} respectively. These burdens are particularly prevalent in high-income countries, such as the USA, where technological advancements have reduced daily PA engagement.^{1 7 9} Thus, identifying minimum effective doses of MPA and/or VPA for producing clinically meaningful mortality risk reduction can crucially inform PA recommendations.

Muscle-strengthening...