Table 2.

Coefficients of Maximal Power Output from Three Models, Based on Data from 9–10-Year-Old Native Tibetan and Han Chinese Children Living in Lhasa at 3700 m and Native Tibetan Children Living in Tingri at 4300 m Above Sea Level^#

Wmax	Coef.	95% confidence interval
Model 1
Constant	85.7**	83.2–88.2
Lhasa Tibetan	0
Tingri Tibetan	−16.4**	−18.8–−14.0
Lhasa Han Chinese	−4.7**	−6.4–−2.9
Sex	−10.6**	−12.2–−9.1
Body mass	1.5**	1.3–1.6
Owning bicycle▴	−4.5**	−6.1–−2.9
Model 2
Constant▵	78.9**	76.4–81.4
Sex	−8.7**	−10.4–−7.1
Body mass	1.3**	1.1–1.5
Owning bicycle▴	−4.4**	−6.–−2.8
[Hb]	0.9*	0.3–1.5
HRpeak	0.4**	0.3–0.4
SaO2rest	0.8**	0.5–1.0
SaO2peak	−0.3*	−0.4–−0.1
FVC	13.2**	9.8–16.5
Model 3
Constant▵	82.5**	80.1–84.9
Lhasa Tibetan	0
Tingri Tibetan	−18.1**	−20.6–−15.5
Lhasa Han Chinese	−4.1**	−5.8–−2.4
Sex	−8.4**	−9.9–−6.9
Body mass	0.9**	0.7–1.0
Owning bicycle▴	−3.5**	−5.0–−2.0
[Hb]	0.3	−0.3–0.9
HRpeak	0.2**	0.2–0.3
SaO2rest	0.4*	0.1–0.6
SaO2peak	−0.6**	−0.7–−0.4
FVC	16.2**	13.1–19.3

^#No bivariate association was found between HR_rest and a maximal power output, thus not included in Models; ^▴Own a bicycle (vs. no bicycle) was set as reference; ^▵when boy is set as reference and body mass=27 kg, [Hb]=14.6g/L, HR_peak=195 beats/min, S_aO_2rest=90%, S_aO_2peak=86%, FVC=2.00; ^*0.001<p<0.01; ^**p<0.001; The explained variance (R²) is 54%; The explained variance (R²) is 63%.