title: Response.
authors.affiliation: Life Science Division Lawrence Berkeley Laboratory Berkeley, CA.
authors.forename: Paul T
authors.initials: PT
authors.lastname: Williams
mesh_terms: D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D012140:Respiratory Tract Diseases / Q000401:mortality*; D040242:Risk Reduction Behavior; D012420:Running / Q000502:physiology*; D016138:Walking / Q000502:physiology*