INS and diabetes mellitus: This study aims to: (a) examine the associations between each individual lipid species and objectively measured physical activity levels at both time points; (b) evaluate whether physical activity-associated lipids are prospectively associated with incident diabetes and prediabetes; (c) assess whether physical activity-associated lipids are longitudinally associated with markers of glucose and insulin homeostasis; and (d) determine whether a lipidomic score of physical activity, derived from the identified lipids, is associated with future diabetes risk.