Table 2.
Participant demographics and results of body impedance analysis and surface electromyography measurements by age group and sex.
| Age Group | 40s | 50s | 60s | 70s | p-Value between Age Groups | ||||
|---|---|---|---|---|---|---|---|---|---|
| n | 40 | 45 | 49 | 45 | |||||
| M (n = 16) |
W (n = 24) |
M (n = 20) |
W (n = 25) |
M (n = 24) |
W (n = 25) |
M (n = 22) |
W (n = 23) |
||
| Age (years) | 45.1 ± 2.6 | 54.1 ± 2.9 | 64.4 ± 3.0 | 74.1 ± 2.6 | - | ||||
| 44.1 ± 2.7 | 45.7 ± 2.4 | 54.6 ± 3.0 | 53.7 ± 2.9 | 65.1 ± 2.6 | 63.6 ± 3.2 | 75.2 ± 2.7 | 73.0 ± 2.1 | ||
| p-Value between sexes | NS | NS | NS | 0.0043 | |||||
| Height (cm) | 165.9 ± 7.8 | 164.1 ± 8.1 | 160.6 ± 9.1 | 161.0 ± 8.4 | 0.0093 | ||||
| 173.1 ± 4.0 | 161.0 ± 5.5 | 171.4 ± 5.2 | 158.4 ± 4.5 | 167.5 ± 6.3 | 154.0 ± 5.7 | 166.6 ± 5.3 | 155.7 ± 7.5 | ||
| p-Value between sexes | <0.0001 | <0.0001 | <0.0001 | <0.0001 | |||||
| BMI (kg/m2) | 24.2 ± 3.4 | 24.8 ± 3.4 | 25.2 ± 2.5 | 23.9 ± 2.6 | NS | ||||
| 26.0 ± 3.0 | 23.0 ± 3.2 | 26.3 ± 2.3 | 23.6 ± 3.7 | 25.5 ± 2.2 | 24.9 ± 2.7 | 23.4 ± 2.8 | 24.5 ± 2.3 | ||
| p-Value between sexes | 0.0053 | 0.0083 | NS | NS | |||||
| Average step length (cm) | 64.4 ± 4.8 | 64.8 ± 5.6 | 62.0 ± 7.0 | 60.2 ± 8.3 | 0.0034 | ||||
| 65.9 ± 4.2 | 63.4 ± 5.0 | 66.8 ± 6.0 | 63.3 ± 4.8 | 64.3 ± 7.3 | 59.7 ± 6.1 | 62.8 ± 8.4 | 57.8 ± 7.5 | ||
| p-Value between sexes | NS | 0.0343 | 0.0183 | 0.0412 | |||||
| ASM (kg/m2) | 7.3 ± 1.1 | 7.3 ± 1.2 | 7.2 ± 1.1 | 6.9 ± 0.9 | NS | ||||
| 8.4 ± 0.5 | 6.5 ± 0.6 | 8.4 ± 0.6 | 6.3 ± 0.6 | 8.0 ± 0.8 | 6.4 ± 0.7 | 7.5 ± 0.7 | 6.3 ± 0.5 | ||
| p-Value between sexes | <0.0001 | <0.0001 | <0.0001 | <0.0001 | |||||
| BFM (kg) | 18.9 ± 6.4 | 19.3 ± 5.8 | 19.0 ± 5.4 | 18.4 ± 6.2 | NS | ||||
| 19.2 ± 6.6 | 18.7 ± 6.4 | 18.9 ± 4.1 | 19.7 ± 6.8 | 18.0 ± 5.2 | 19.9 ± 5.4 | 15.6 ± 5.9 | 21.1 ± 5.3 | ||
| p-Value between sexes | NS | NS | NS | 0.0017 | |||||
| Average RMS: knee flexion (µV) | 348.4 ± 165.1 | 334.2 ± 123.9 | 345.1 ± 112.4 | 260.2 ± 91.8 | 0.0024 | ||||
| 409.6 ± 165.5 | 307.6 ± 155.0 | 356.0 ± 117.1 | 316.7 ± 128.8 | 386.6 ± 115.4 | 305.2 ± 95.6 | 310.7 ± 97.1 | 211.8 ± 53.3 | ||
| p-Value between sexes | NS | NS | 0.0098 | 0.0001 | |||||
| Average RMS: knee extension (µV) | 246.0 ± 99.8 | 265.2 ±105.4 | 227.9 ± 87.4 | 194.8 ± 98.9 | 0.0068 | ||||
| 267.2 ± 112.0 | 231.9 ± 90.4 | 282.9 ± 103.8 | 251.1 ± 106.5 | 252.5 ± 102.9 | 204.3 ± 62.7 | 214.2 ± 120.1 | 176.3 ± 71.2 | ||
| p-Value between sexes | NS | NS | NS | NS | |||||
Data are presented as mean ± SD; 40s, age 40–49 years; 50s, age 50–59 years; 60s, age 60–69 years; 70s, age 70–79 years; M, men; W, women; NS, not significant; BMI, body mass index; ASM, appendicular skeletal muscle mass; BFM, body fat mass; RMS, root mean square.