Mean and SD of body mass (in kilograms) and height (in metres) of international rugby union players taking part in the opening matches of the Five or Six Nations tournament in 1955, 1965, 1975, 1985, 1995, 2005 and 2015 divided by position (n=5 for hookers; n=10 for props, second rows, half-backs; n=15 for back-row, centres and back three)
| Year | 1955 | 1965 | 1975 | 1985 | Change 1955–1985 (%) | 1995 | 2005 | 2015 | Change 1995–2015 (%) |
| Body mass | |||||||||
| Prop | 90.3 (6.1) | 94.9 (4.0) | 97.3 (4.1) | 103.4 (3.5) | 14.5 | 106.1 (2.9) | 114.2 (6.8) | 116.9 (4.9) | 10.2 |
| Hooker | 84.8 (7.8) | 85.7 (6.5) | 90.1 (4.6) | 89.1 (5.7) | 5.1 | 98.9 (5.0) | 101.2 (8.2) | 110.2 (3.3) | 11.4 |
| Second row | 94.3 (7.5) | 99.9 (3.6) | 103.0 (3.6) | 106.1 (4.5) | 12.5 | 115.3 (6.1) | 116.0 (2.8) | 119.7 (4.0) | 3.8 |
| Back-row | 85.7 (5.2) | 90.7 (5.4) | 92.3 (3.9) | 95.9 (6.0) | 11.9 | 102.7 (8.0) | 104.3 (6.9) | 109.6 (5.6) | 6.7 |
| Half-back | 76.0 (7.9) | 74.6 (5.9) | 74.8 (4.7) | 76.3 (5.8) | 0.0 | 79.1 (3.9) | 83.3 (6.8) | 88.8 (4.4) | 12.3 |
| Centre | 82.0 (5.6) | 79.4 (7.5) | 80.9 (6.1) | 80.1 (7.3) | −2.3 | 86.7 (3.1) | 92.9 (8.1) | 100.9 (12.4) | 16.4 |
| Back 3 | 81.6 (5.3) | 75.6 (8.6) | 79.3 (6.8) | 79.2 (4.8) | −2.9 | 87.4 (4.4) | 90.4 (8.9) | 96.3 (6.4) | 10.2 |
| Height | |||||||||
| Prop | 1.80 (0.02) | 1.81 (0.02) | 1.81 (0.05) | 1.81 (0.03) | 0.6 | 1.80 (0.03) | 1.85 (0.04) | 1.85 (0.04) | 2.8 |
| Hooker | 1.78 (0.05) | 1.82 (0.03) | 1.79 (0.02) | 1.78 (0.02) | 0.6 | 1.79 (0.04) | 1.82 (0.04) | 1.83 (0.02) | 2.2 |
| Second row | 1.87 (0.02) | 1.93 (0.05) | 1.95 (0.03) | 1.95 (0.05) | 4.3 | 2.00 (0.04) | 1.99 (0.03) | 2.00 (0.04) | 0.0 |
| Back-row | 1.82 (0.04) | 1.85 (0.04) | 1.88 (0.05) | 1.91 (0.04) | 3.3 | 1.93 (0.04) | 1.91 (0.05) | 1.91 (0.03) | −1.0 |
| Half-back | 1.75 (0.03) | 1.72 (0.07) | 1.74 (0.06) | 1.78 (0.06) | −0.6 | 1.77 (0.03) | 1.77 (0.05) | 1.81 (0.05) | 2.3 |
| Centre | 1.80 (0.04) | 1.77 (0.05) | 1.81 (0.07) | 1.80 (0.05) | 0.6 | 1.83 (0.02) | 1.84 (0.05) | 1.87 (0.05) | 2.2 |
| Back 3 | 1.80 (0.04) | 1.78 (0.07) | 1.80 (0.06) | 1.79 (0.05) | 0.0 | 1.81 (0.05) | 1.84 (0.08) | 1.87 (0.05) | 3.3 |