Table 3.

Results of hierarchical regression models to elucidate the relationship between peak VO₂ and FA in OA

	R-value	ΔR2	ΔF	Model F-value
Right temporal pole
Step 1 (peak VO2)	0.59	0.35	13.26, P < 0.001	13.26, P < 0.001
Step 2 (age, gender, educ, CES-D)	0.71	0.15	1.58, P = ns	4.17, P < 0.01
Right fornix (stria terminalis)
Step 1 (peak VO2)	0.47	0.22	6.95, P < 0.05	6.95, P < 0.05
Step 2 (age, gender, educ, CES-D)	0.68	0.24	2.31, P = ns	3.53, P < 0.05
Left sagittal stratum
Step 1 (peak VO2)	0.63	0.39	16.20, P < 0.001	16.20, P < 0.001
Step 2 (age, gender, educ, CES-D)	0.76	0.18	2.22, P = ns	5.65, P < 0.005
Right posterior corona radiata
Step 1 (peak VO2)	0.61	0.37	14.51, P < 0.001	14.51, P < 0.001
Step 2 (age, gender, educ, CES-D)	0.74	0.18	2.02, P = ns	4.99, P < 0.01
Body of the cc
Step 1 (peak VO2)	0.54	0.29	10.16, P < 0.005	10.16, P < 0.005
Step 2 (age, gender, educ, CES-D)	0.72	0.23	2.43, P = ns	4.45, P < 0.01

FA, fractional anisotropy; OA, older adults; cc, corpus callosum; CES-D, Center for Epidemiologic Studies Depression Scale.