Vigorous exercise at baseline in relation to incidence of breast cancer overall and ER+ and ER− breast cancer
| All breast cancer | ER+ breast cancer | ER− breast cancer | |||||
|---|---|---|---|---|---|---|---|
| h/wk | Cases | Person-years | IRRa (95% CI) | Cases | IRR (95% CI) | Cases | IRR (95% CI) |
| <1 | 773 | 313,900 | 1.00 (Ref.) | 382 | 1.00 (Ref.) | 228 | 1.00 (Ref.) |
| 1 | 117 | 62,939 | 0.85 (0.70–1.03) | 59 | 0.86 (0.66–1.14) | 35 | 0.83 (0.58–1.18) |
| 2 | 149 | 67,081 | 0.99 (0.83–1.19) | 76 | 1.00 (0.78–1.29) | 45 | 1.00 (0.72–1.38) |
| 3–4 | 159 | 77,243 | 0.94 (0.79–1.12) | 84 | 0.98 (0.77–1.25) | 45 | 0.88 (0.63–1.22) |
| 5–6 | 69 | 35,793 | 0.89 (0.69–1.14) | 36 | 0.92 (0.65–1.30) | 23 | 0.97 (0.63–1.50) |
| ≥7 | 63 | 39,593 | 0.74 (0.57–0.96) | 32 | 0.75 (0.52–1.09) | 22 | 0.85 (0.55–1.33) |
| Ptrend = 0.05 | Ptrend = 0.28 | Ptrend = 0.43 | |||||
↵aIRRs adjusted for age (single year), time period (questionnaire cycle), years of education (≤12, 13–15, 16, ≥17), parity (0, 1, 2, ≥3), vegetable/fruit dietary pattern (quintiles), and meat/fried foods dietary pattern (quintiles)