Introduction
Materials and methods
Subjects
Present physical activity
Anthropometrics, calcium intake, and smoking status
Grip strength
Areal BMD and body composition
Cortical bone geometry and volumetric BMD
Bone microarchitectural measurement
Statistical analysis
Results
Characteristics
Non-athletic referents | Type of exercise | ANOVA p
| ANCOVA p
| ||
---|---|---|---|---|---|
Resistance training | Soccer | ||||
Number of subjects | 177 | 106 | 78 | ||
Age (years) | 24.2 ± 0.6 | 24.0 ± 0.7 | 23.9 ± 0.6a | 0.031 | |
Height (cm) | 181.9 ± 6.8 | 182.4 ± 6.8 | 180.6 ± 6.6 | 0.819 | |
Weight (kg) | 79.2 ± 15.9 | 78.8 ± 11.1 | 80.2 ± 10.7 | 0.772 | |
Calcium intake (mg/day) | 793 ± 527 | 836 ± 579 | 781 ± 414 | 0.733 | |
Lean mass (kg)a
| 56.3 ± 6.1 | 59.4 ± 5.8A
| 61.4 ± 6.3A
| <0.001 | |
Adjusted lean mass (kg)a
| 56.5 ± 3.7 | 59.3 ± 4.2A
| 61.1 ± 3.9A,B | <0.001 | |
Fat mass (kg)a
| 19.8 ± 10.7 | 16.8 ± 8.1a | 15.4 ± 6.1A | 0.001 | |
Fat percenta
| 23.7 ± 8.9 | 20.5 ± 7.2A | 18.8 ± 6.0A
| <0.001 | |
Grip strength (kg)b
| 48.6 ± 10.5 | 53.0 ± 9.2A | 51.1 ± 9.9 | 0.002 | |
Adjusted grip strength (kg)b
| 48.6 ± 10.3 | 53.0 ± 9.0A | 50.9 ± 9.4 | 0.001 | |
Smoking (%) | 16.9 | 5.6A | 1.3A
| ||
Occupational physical loading (MET) | 3.1 ± 2.9 | 3.5 ± 2.9 | 3.5 ± 2.9 | 0.434 | |
Sedentary behavior (h/week) | 25.5 ± 17.6 | 25.1 ± 22.7 | 22.2 ± 18.9 | 0.455 | |
Daily transportation | |||||
Walking (%) | 15.3 | 10.2 | 10.3 | ||
Bicycling (%) | 11.3 | 12.0 | 9.0 | ||
Passive transportation (%) | 73.4 | 77.8 | 80.8 | ||
Specific sport | |||||
Duration of training (h/week) | – | 3.0 ± 2.3 | 3.8 ± 2.2b | ||
History of training (year) | – | 5.1 ± 3.4 | 14.9 ± 5.6B
| ||
All sports | |||||
Duration of training (h/week) | – | 4.1 ± 2.7 | 5.7 ± 2.8B
| ||
History of training (year) | – | 5.6 ± 4.1 | 15.3 ± 5.1B
|
Association between type of exercise loading and bone parameters
Non-athletic referents | Type of exercise | ANOVA p
| ||
---|---|---|---|---|
Resistance training | Soccer | |||
Number of subjects | 177 | 106 | 78 | |
Areal bone mineral density | ||||
Total body (g/cm2)a
| 1.25 ± 0.09 | 1.27 ± 0.09 | 1.36 ± 0.09A,B
| <0.001 |
Lumbar spine (g/cm2)a
| 1.21 ± 0.13 | 1.23 ± 0.14 | 1.36 ± 0.15A,B
| <0.001 |
Femoral neck (g/cm2)a
| 1.06 ± 0.14 | 1.07 ± 0.15 | 1.26 ± 0.17A,B
| <0.001 |
Total hip (g/cm2)a
| 1.08 ± 0.14 | 1.09 ± 0.16 | 1.29 ± 0.17A,B
| <0.001 |
Radius nondominant (g/cm2) | 0.62 ± 0.06 | 0.63 ± 0.05 | 0.63 ± 0.05 | 0.126 |
Tibial diaphysis | ||||
Cortical cross-sectional area (mm2) | 266 ± 33 | 275 ± 37 | 310 ± 34A,B
| <0.001 |
Cortical periosteal circumference (mm) | 73.1 ± 4.8 | 74.0 ± 4.8 | 76.8 ± 4.3A,B
| <0.001 |
Cortical thickness (mm) | 4.54 ± 0.47 | 4.63 ± 0.57 | 5.13 ± 0.56A,B
| <0.001 |
Cortical endosteal circumference (mm) | 44.5 ± 5.2 | 44.9 ± 5.3 | 44.5 ± 5.5 | 0.818 |
Cortical volumetric density (mg/cm3) | 1,169 ± 17 | 1,164 ± 19 | 1,155 ± 21A,B | <0.001 |
Radial diaphysis | ||||
Cortical cross-sectional area (mm2) | 95.6 ± 12.9 | 98.9 ± 11.9 | 100.7 ± 11.0A | 0.004 |
Cortical periosteal circumference (mm) | 41.4 ± 3.1 | 42.2 ± 2.9 | 42.7 ± 2.8A | 0.002 |
Cortical volumetric density (mg/cm3) | 1,194 ± 16 | 1,188 ± 17a | 1,189 ± 17 | 0.007 |
Tibial metaphysis | ||||
Trabecular bone volume fraction (%)b
| 17.6 ± 2.6 | 17.5 ± 2.6 | 20.3 ± 2.3A,B
| <0.001 |
Trabecular number (mm−1)b
| 2.07 ± 0.28 | 2.04 ± 0.28 | 2.25 ± 0.27A,B
| <0.001 |
Trabecular volumetric density (mg/cm3)b
| 211.6 ± 31.1 | 210.5 ± 31.5 | 243.2 ± 28.3A,B
| <0.001 |
Trabecular separation (mm)b
| 0.41 ± 0.07 | 0.41 ± 0.07 | 0.36 ± 0.05A,B
| <0.001 |
Trabecular thickness (μm)b
| 85.9 ± 11.0 | 86.8 ± 12.2 | 90.8 ± 11.0A | 0.007 |
Cortical volumetric density (mg/cm3)b
| 874 ± 35 | 867 ± 33 | 872 ± 30 | 0.245 |
Radial metaphysis | ||||
Trabecular bone volume fraction (%)c
| 16.3 ± 2.9 | 16.5 ± 2.8 | 17.3 ± 2.7a | 0.035 |
Trabecular number (mm−1)c
| 2.1 ± 0.3 | 2.1 ± 0.2 | 2.1 ± 0.3 | 0.675 |
Trabecular separation (mm)c
| 0.40 ± 0.06 | 0.41 ± 0.06 | 0.40 ± 0.06 | 0.593 |
Trabecular thickness (μm)c
| 77.5 ± 12.4 | 79.4 ± 12.1 | 82.5 ± 12.9a | 0.021 |
Cortical volumetric density (mg/cm3)c
| 851 ± 43 | 840 ± 40 | 852 ± 39 | 0.064 |
Non-athletic referents | Type of exercise | ANCOVA1 p
| ANCOVA2 p
| ||
---|---|---|---|---|---|
Resistance training | Soccer | ||||
Number of subjects | 177 | 106 | 78 | ||
Areal bone mineral density | |||||
Total body (g/cm2)a
| 1.26 ± 0.07 | 1.27 ± 0.09 | 1.36 ± 0.08A,B
| <0.001 | <0.001 |
Lumbar spine (g/cm2)a
| 1.21 ± 0.12 | 1.23 ± 0.14 | 1.35 ± 0.14A,B
| <0.001 | <0.001 |
Femoral neck (g/cm2)a
| 1.06 ± 0.13 | 1.07 ± 0.15 | 1.26 ± 0.17A,B
| <0.001 | <0.001 |
Total hip (g/cm2)a
| 1.08 ± 0.13 | 1.09 ± 0.16 | 1.28 ± 0.16A,B
| <0.001 | <0.001 |
Radius nondominant (g/cm2) | 0.62 ± 0.05 | 0.63 ± 0.05 | 0.63 ± 0.04 | 0.176 | 0.169 |
Tibial diaphysis | |||||
Cortical cross-sectional area (mm2) | 267 ± 26 | 275 ± 32 | 309 ± 28A,B
| <0.001 | <0.001 |
Cortical periosteal circumference (mm) | 73.2 ± 3.3 | 74.0 ± 3.7 | 76.5 ± 3.3A,B
| <0.001 | <0.001 |
Cortical thickness (mm) | 4.54 ± 0.46 | 4.63 ± 0.55 | 5.12 ± 0.55A,B
| <0.001 | <0.001 |
Cortical endosteal circumference (mm) | 44.6 ± 4.4 | 44.9 ± 4.7 | 44.4 ± 4.9 | 0.773 | 0.766 |
Cortical volumetric density (mg/cm3) | 1,168 ± 16 | 1,164 ± 18 | 1,156 ± 20A,B | <0.001 | <0.001 |
Radial diaphysis | |||||
Cortical cross-sectional area (mm2) | 95.8 ± 11.4 | 98.9 ± 11.1 | 100.3 ± 10.0A | 0.005 | 0.007 |
Cortical periosteal circumference (mm) | 41.4 ± 2.6 | 42.2 ± 2.6a | 42.6 ± 2.5A | 0.001 | 0.002 |
Cortical volumetric density (mg/cm3) | 1,194 ± 16 | 1,188 ± 16a | 1,190 ± 17 | 0.008 | 0.006 |
Tibial metaphysis | |||||
Trabecular bone volume fraction (%)b
| 17.6 ± 2.5 | 17.5 ± 2.6 | 20.2 ± 2.4A,B
| <0.001 | <0.001 |
Trabecular number (mm−1)b
| 2.07 ± 0.23 | 2.04 ± 0.26 | 2.23 ± 0.24A,B
| <0.001 | <0.001 |
Trabecular volumetric density (mg/cm3)b
| 211.7 ± 30.3 | 210.6 ± 31.7 | 242.7 ± 28.6A,B
| <0.001 | <0.001 |
Trabecular separation (mm)b
| 0.41 ± 0.06 | 0.41 ± 0.06 | 0.36 ± 0.05A,B
| <0.001 | <0.001 |
Trabecular thickness (μm)b
| 85.8 ± 10.5 | 86.7 ± 11.6 | 91.2 ± 9.6A,b | 0.001 | 0.025 |
Cortical volumetric density (mg/cm3)b
| 873 ± 29 | 867 ± 30 | 873 ± 27 | 0.243 | 0.182 |
Radial metaphysis | |||||
Trabecular bone volume fraction (%)c
| 16.2 ± 2.9 | 16.5 ± 2.8 | 17.3 ± 2.7a | 0.043 | 0.084 |
Trabecular number (mm−1)c
| 2.1 ± 0.2 | 2.1 ± 0.2 | 2.1 ± 0.2 | 0.679 | 0.673 |
Trabecular separation (mm)c
| 0.40 ± 0.06 | 0.41 ± 0.06 | 0.40 ± 0.06 | 0.674 | 0.620 |
Trabecular thickness (μm)c
| 77.3 ± 12.4 | 79.5 ± 11.9 | 82.4 ± 12.4a | 0.016 | 0.057 |
Cortical volumetric density (mg/cm3)c
| 850 ± 41 | 840 ± 35 | 851 ± 35 | 0.089 | 0.057 |