Modeling the Effect of Competitive Level of Female Athletes on Bone Mass Density in the Upper Arm of Female Participants Using Weighted Least Squares Linear Regression*
| Variable | Effect (β) | 95% CI for β |
|---|---|---|
| Elite athleticism† | 0.140 | 0.047–0.234 |
| Competive‡ | 0.010 | −0.095 to 0.115 |
| Active control§ | 0.045 | −0.051 to 0.14 |
| Upper extremity impact¶ | 0.037 | −0.025 to 0.099 |
| Age | 0.009 | −0.001 to 0.019 |
| BMI | 0.023 | −0.001 to 0.047 |
| Constant | 0.132 | −0.437 to 0.701 |
| F (p) = 6.353 (P < .000) | R2 = 0.536 |
↵* The β coefficient indicates the estimated effect size of each variable. The model indicates that elite athleticism, defined as participation in Division I–level competitive sport at the time of measurement, significantly predicts an increase of bone mass density in the upper arm by 0.140 g/cm−2, when age, impact level of sport, and body mass index are controlled. Each variable was entered as the mean for each study group.
↵† Elite athletes included NCAA Division I competitors.
↵‡ Competitive collegiate athletes included NCAA Division II or III competitors.
↵§ Noncompetitive athletes, eg, joggers, noncompetitive swimmers, and intramurals.
↵¶ Basketball, boxing, gymnastics, handball, and volleyball = 1 versus 0 for low impact and control.
BMI, body mass index.