Table 3.

Regression models for aerobic capacity

Independent variables	Aerobic capacity (peakVO2, in l/min)
	β	P-value	R2
Simple regression analysis
Personal characteristics
Gender	−0.61	<0.001	0.36
Age	−0.07	0.65	–
Lesion level	−0.43	0.002	0.17
Hydrocephalus	−0.18	0.22	–
Ambulatory status	−0.48	<0.001	0.22
Educational level	0.13	0.39	–
Multiple regression analysis
Step 1a
Personal characteristics			0.50
Gender	−0.55	<0.001
Ambulatory status	−0.40	<0.001
Step 2b
Inter-relations
Muscle strength (Z-score)	0.22	0.04	0.55
Body composition (sum of four skin-folds in mm)	0.25	0.08	0.53
Joint mobility (number of restricted joints)	0.00	0.98	–

Significant betas are presented in bold

β standardized regression coefficient, R² explained variance, Gender male (0), female (1), Lesion level sacral (1), lumbosacral (2), lumbar (3), thoracolumbar (4), thoracic (5), Hydrocephalus no (0), yes (1), Ambulatory status community ambulator (1), household ambulator (2), non(functional) ambulator (3), Educational level: low (0), medium (1), high (2)

^aDue to large overlap between ambulatory status and lesion level, we only included ambulatory status

^bRelations between aerobic capacity and other fitness components controlled for gender and ambulatory status