Table 1.
Included studies categorized by study characteristics
| Number of studies | % | Reference numbers | |
|---|---|---|---|
| Risk of bias | |||
| Low | 30 | 38% | [1, 2, 4, 12, 14–16, 18, 20, 23–26, 31, 34, 36, 40, 42–44, 49, 50, 57, 59, 60, 62, 67, 75–77] |
| Medium | 41 | 53% | [5–9, 13, 17, 21, 22, 28–30, 32, 33, 35, 37–39, 45–48, 51, 55, 56, 58, 61, 63–66, 68–74, 78] |
| High | 7 | 9% | [3, 19, 27, 41, 52–54] |
| Sample size | |||
| < 100 | 5 | 6% | [5, 17, 41, 53, 71] |
| 100–299 | 19 | 24% | [4, 6, 7, 9, 10, 13, 21, 27, 29, 32, 48, 51, 52, 66, 68, 70, 73, 75, 76] |
| 300–499 | 9 | 12% | [3, 8, 16, 33, 38, 39, 49, 72, 78] |
| 500–1999 | 25 | 32% | [15, 18, 19, 22–26, 30, 31, 35, 40, 43, 44, 46, 47, 50, 54, 55, 60, 61, 63, 65, 69, 74] |
| 2000–4999 | 14 | 18% | [1, 12, 14, 20, 34, 36, 42, 45, 56, 57, 59, 62, 67, 77] |
| > 5000 | 6 | 8% | [2, 11, 28, 37, 58, 64] |
| Region | |||
| North America | 31 | 40% | [1, 2, 4, 5, 10–12, 14, 17, 19, 21, 22, 28, 33, 34, 37, 42–44, 50–53, 57, 59, 60, 63, 65, 67, 69, 77] |
| Europe | 29 | 37% | [6, 7, 18, 20, 23–27, 29, 30, 36, 38, 40, 45, 47–49, 55, 56, 62, 64, 66, 70, 71, 75, 76] |
| Asia | 14 | 18% | [13, 16, 32, 35, 39, 41, 54, 58, 61, 68, 72–74, 78] |
| Oceania (including Australia) | 4 | 5% | [3, 15, 31, 46] |
| World Bank income classification | |||
| High-income countries | 74 | 95% | [1–29, 33–60, 62–71, 74–78] |
| Upper-middle-income countries | 2 | 3% | [72, 73] |
| Lower-middle-income countries | 2 | 3% | [32, 61] |
| Low-income countries | 0 | 0% | – |
| Country | |||
| Canada | 1 | 1% | [51] |
| United States | 30 | 38% | [1, 2, 4, 5, 10–12, 14, 17, 19, 21, 22, 28, 33, 34, 37, 42–44, 50, 52, 53, 57, 59, 60, 63, 65, 67, 69, 77] |
| Finland | 5 | 6% | [23, 30, 45, 47, 66] |
| Sweden | 3 | 4% | [6, 7, 64] |
| Norway | 3 | 4% | [18, 55, 62] |
| Netherlands | 4 | 5% | [8, 38, 70, 71] |
| Germany | 6 | 8% | [20, 25, 26, 29, 36, 40] |
| United Kingdom | 2 | 3% | [24, 49] |
| Belgium | 2 | 3% | [48, 76] |
| Lithuania | 1 | 1% | [27] |
| Italy | 1 | 1% | [56] |
| Spain | 1 | 1% | [75] |
| Israel | 3 | 4% | [16, 35, 58] |
| Jordan | 1 | 1% | [32] |
| India | 1 | 1% | [61] |
| China | 2 | 3% | [72, 73] |
| Korea | 2 | 3% | [39, 78] |
| Japan | 5 | 6% | [13, 41, 54, 68, 74] |
| Australia | 2 | 3% | [15] |
| New Zealand | 2 | 3% | [31, 46] |
| Multiple countries | 1 | 1% | [9] |
| Study design | |||
| Cross-sectional | 59 | 76% | [1–3, 9–14, 16, 18–21, 23–30, 32–36, 39–45, 47–52, 54, 56–59, 61, 62, 65–69, 72, 74, 75, 77, 78] |
| Longitudinal | 18 | 23% | [6, 15, 17, 22, 31, 37, 38, 46, 53, 55, 60, 63, 64, 70, 73, 76] |
| Case–control | 1 | 1% | [71] |
| Sex | |||
| Women only | 8 | 10% | [13, 19, 28, 39, 52, 53, 63, 73] |
| Men only | 17 | 22% | [3, 5, 10, 17, 23, 32, 35, 45, 47, 48, 50, 55, 56, 61, 64, 74, 76] |
| Women and men | 48 | 62% | [2, 4, 6–8, 11, 12, 14–16, 18, 20–22, 24–27, 29, 30, 33, 34, 36–38, 40–44, 49, 51, 54, 57–60, 65–72, 75, 78, 79] |
| NR | 5 | 6% | [1, 9, 31, 46, 62] |
| Maximal or submaximal exercise testing | |||
| Maximal | 48 | 62% | [8, 11–13, 16–18, 21–23, 25–30, 33–40, 45, 47, 48, 51–53, 55–57, 59–61, 63–66, 69–71, 73–75, 77] |
| Submaximal | 27 | 35% | [1, 5–7, 9, 14, 15, 19, 20, 24, 31, 41–44, 46, 49, 50, 54, 58, 62, 67, 68, 72, 76] |
| NR | 3 | 4% | [10, 32, 78] |
| Exercise test machine | |||
| Cycle | 34 | 44% | [3, 5–7, 9, 13, 15, 20, 23–27, 30–32, 36, 40, 45–48, 51, 55, 56, 64, 66, 68, 71–76] |
| Treadmill | 44 | 56% | [1, 2, 4, 8, 10–12, 14, 16–19, 21, 22, 28, 29, 33–35, 37–39, 41–44, 49, 50, 52–54, 57–63, 65, 67, 69, 70, 77, 78] |
| CRF measure | |||
| VO2max, direct (among others) | 39 | 50% | [4, 5, 8, 10, 13, 17, 18, 21–27, 29, 30, 33, 35, 38–40, 45, 47–49, 51–54, 62, 65, 66, 69–73, 75, 76] |
| VO2max indirect (among others) | 19 | 24% | [1, 6, 7, 9, 14, 16, 31, 41–44, 46, 50, 67, 68, 74, 77] |
| Only other measures | 19 | 24% | [11, 12, 15, 19, 20, 28, 32, 34, 36, 37, 55–61, 63, 64] |
| NR | 1 | 1% | [78] |
CRF cardiorespiratory fitness, NR not reported, VO2max maximal oxygen consumption