Table 4. Isotemporal substitution a of activities, per 20 min/day increase, and 12-year relative waist circumference change (cm) from 1996-2008 among 10,500 men in the Health Professional Follow-up Study.
| Analysis Methods | TV watching | Moderate-to-vigorous aerobic exercise | Weight training | Other activities | Total discretionary Time b |
|---|---|---|---|---|---|
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| β0 (95%CI) | β1 (95%CI) | β2 (95%CI) | β3 (95%CI) | β4 (95%CI) | |
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| Substitution of a 20-min/day of an activity to replace a 30 min/day of TV watching c | |||||
| Substitution model (b) | Dropped | -0.42 (-0.50, -0.34) | -0.76 (-1.02, -0.50) | -0.24 (-0.37, -0.11) | 0.08 (0.05, 0.12) |
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| Substitution of a 20-min/day of an activity to replace a 30 min/day of moderate-to-vigorous aerobic exercise c | |||||
| Substitution model (c) | 0.41 (0.33, 0.49) | Dropped | -0.34 (-0.62, -0.07) | 0.17 (0.03, 0.31) | -0.33 (-0.39, -0.26) |
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| Substitution of a 20-min/day of an activity to replace a 30 min/day of weight training c | |||||
| Substitution model (d) | 0.75 (0.49, 1.01) | 0.34 (0.07, 0.62) | Dropped | 0.52 (0.23, 0.80) | -0.67 (-0.93, -0.41) |
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| Substitution of a 20-min/day of an activity to replace a 30 min/day of other activities c | |||||
| Substitution model (e) | 0.24 (0.11, 0.37) | -0.17 (-0.31, -0.03) | -0.52 (-0.80, -0.23) | Dropped | -0.15 (-0.28, -0.03) |
Each regression coefficient (95% CI) represents a comparison of waist circumference (in cm) for every 20 min/day increase in the predictor variable replacing 20 min/day of the activity that is dropped out of the model.
Total discretionary time” includes total discretionary physical activity and TV watching
All models are adjusted for baseline (1996) age (years) and waist circumference (continuous, cm), total average alcohol intake (1994, 2006); sugar-sweetened beverage intake (1994, 2006); percent energy of trans-fat (1994, 2006); energy-adjusted fibers (1994, 2006), energy-adjusted glycemic load (1994, 2006); smoking (1996, 2008), anti-depressant intake (1996, 2008), percent energy of protein intake, (1994, 2006), sleep duration (2000, 2008), slow walking (1996, 2008) (min/day, continuous); in addition to TV watching, moderate-to-vigorous aerobic activity, weight training, and other activities (all in 1996) (all continuous, min/day). The corresponding physical activity would be dropped in 1996 if it was dropped outside the model in 2008.