Figure 2. Dose-response relationship between total muscle-strengthening activity (hours/week) and risk of type 2 diabetes in women from the Nurses' Health Study II.

Dotted lines are 95% CI for the trend obtained from restricted cubic spline regression (3 knots) truncated at 7 hours/week (≈99th percentile). Estimates were adjusted for age (months), smoking (never, past, or current), alcohol consumption (0, 1–5, >5 g/d), coffee intake (0, <1, 1–3, 3–5, >5 cups/day), race (white, non-white), family history of diabetes, post menopausal hormone use (never, past, current), intake of total energy, trans fat, polyunsaturated fat to saturated fat ratio, cereal fiber, wholegrain, and glycemic load (all dietary factors in quintiles), oral contraceptive use (never, past, current), menopausal status (pre, post), and aerobic physical activity (0, 1–29, 30–59, 60–150, >150 min/week). p = 0.02 for non-linear response.