Table 5.
Sample characteristics. Difference between the age groups was tested using independent samples t-tests (two-tailed, bootstrap statistics).
| Characteristics | Young Mean ± SD | Older Mean ± SD | Mean Difference (95% CI) | p | d |
|---|---|---|---|---|---|
| Physical activity and fitness | |||||
| Six-minute walk test distance (metres, more = better) | — | 580 ± 97 | |||
| Percent fat | — | 39.3 ± 7.1 | |||
| BMI | 22.5 ± 2.7 | 27.1 ± 4.4 | 4.6 (3.4 to 6.1) | 0.001 | 1.11 |
| Self-reported physical activity (hrs/week) | 4.1 ± 1.1 | 3.1 ± 1.4 | |||
| Principal components of cognitive test scores (rotated factor loadings) | |||||
| Executive function | 0.89 ± 0.58 | 0.42 ± 0.87 | 1.3 (1.0 to 1.6) | 0.001 | 1.55 |
| Error susceptibility | 0.07 ± 0.61 | 0.03 ± 1.14 | −0.1 (−0.5 to 0.3) | 0.440 | 0.12 |
| Explicit memory | 0.62 ± 0.68 | 0.29 ± 0.93 | 0.9 (0.6 to 1.2) | 0.001 | 0.93 |
| Working memory | 0.60 ± 0.89 | 0.28 ± 0.93 | 0.9 (0.5 to 1.2) | 0.001 | 0.87 |
| Cognitive test scores | |||||
| Tapping right (clicks/10 s, more = better) | 53 ± 5 | 41 ± 5 | 12 (10 to 14) | 0.001 | 2.28 |
| Tapping left (clicks/10 s, more = better) | 47 ± 5 | 37 ± 5 | 10 (8 to 12) | 0.001 | 1.87 |
| TMT-A (seconds, less = better) | 25 ± 7 | 42 ± 14 | 17 (12 to 22) | 0.001 | 1.29 |
| TMT-B (seconds, less = better) | 51 ± 18 | 96 ± 44 | 45 (30 to 60) | 0.001 | 1.11 |
| Logical memory (points, more = better) | 28 ± 5 | 22 ± 6 | 6 (4 to 8) | 0.001 | 0.97 |
| Logical memory delayed (points, more = better) | 26 ± 6 | 18 ± 7 | 8 (5 to 10) | 0.001 | 1.08 |
| Stroop 1 – reading (seconds, faster = better) | 48 ± 7 | 56 ± 9 | 7 (4 to 11) | 0.001 | 0.78 |
| Stroop 2 – colour labelling (seconds, less = better) | 62 ± 10 | 78 ± 17 | 16 (10 to 22) | 0.001 | 1.00 |
| Stroop 3 – inhibition (seconds, less = better) | 91 ± 21 | 138 ± 35 | 47 (35 to 59) | 0.001 | 1.43 |
| Stroop 2 errors (points, less = better) | 1 ± 1 | 1 ± 2 | 0.7 (0.1 to 1.3) | 0.018 | 0.40 |
| Stroop 3 errors (points, less = better) | 1 ± 1 | 3 ± 5 | 1.9 (0.3 to 3.6) | 0.012 | 0.44 |
| Visual reproduction (points, more = better) | 37 ± 4 | 34 ± 5 | 3 (1 to 5) | 0.001 | 0.61 |
| Visual reproduction delayed (points, more = better) | 36 ± 4 | 30 ± 8 | 6 (3 to 8) | 0.001 | 0.75 |
| Digit span (points, more = better) | 8 ± 2 | 7 ± 2 | 1.1 (0.4 to 1.8) | 0.002 | 0.58 |
| Digit span backwards (points, more = better) | 7 ± 2 | 6 ± 2 | 1.2 (0.5 to 1.8) | 0.001 | 0.66 |
| Digit-letter (points, more = better) | 12 ± 3 | 9 ± 3 | 2.4 (1.3 to 3.5) | 0.001 | 0.79 |
SD, standard deviation. P, statistical significance; d, Cohen’s d.