Table 3.

Morphological data of HCR and LCR at the time of euthanasia 24 h after the last exercise session or in sedentary animals determined during hyperinsulinemic-euglycemic clamp

	Sedentary		Exercise		Effect of Intrinsic Exercise Capacity	Effect of Acquired Exercise Capacity	Interaction between Intrinsic + Extrinsic Capacity
	HCR	LCR	HCR	LCR
Animal age, mo	8.82 ± 0.20	10.03 ± 0.16 b	7.99 ± 0.24a	8.89 ± 0.23ab	<0.001	<0.001	ns
Body weight, g	379 ± 19	523 ± 16b	313 ± 9a	441 ± 10ab	<0.001	<0.001	ns
Body weight change with 20 days of exercise resp. sedentary time, g	18.3 ± 2.2	15.7 ± 3.9	−38.0 ± 7.0a	−7.4 ± 7.4ab	0.03	<0.001	0.012
Body weight change with 20 days of exercise resp. sedentary time, %	4.9 ± 0.6	3.2 ± 0.8	−10.3 ± 1.8a	−1.5 ± 1.6ab	0.018	<0.001	<0.001
Tibia length, mm	41.6 ± 0.5	44.0 ± 0.3b	40.8 ± 0.4	43.0 ± 0.3ab	<0.001	0.015	ns
Heart weight/TL, g/m	27.5 ± 1.1	28.8 ± 1.1	26.2 ± 1.0	28.3 ± 1.02	ns	ns	ns
Ventricle weight/TL, g/m	24.5 ± 1.0	25.9 ± 1.0	22.8 ± 0.6	24.6 ± 0.6	ns	ns	ns
Lung weight/TL, g/m	36.3 ± 1.4	33.6 ± 1.2	39.3 ± 3.0	38.4 ± 1.6	ns	0.046	ns
Liver weight/TL, g/m	216 ± 11	256 ± 11 b	187 ± 7a	214 ± 7 ab	<0.001	<0.001	ns
Pancreas weight/TL, g/m	16.6 ± 1.2	15.4 ± 0.8	16.1 ± 1.1	16.7 ± 1.2	ns	ns	ns
Spleen weight/TL, g/m	17.1 ± 1.1	16.2 ± 0.6	12.0 ± 0.9a	14.7 ± 0.5 b	nd	nd	0.027
Kidney weight/TL, g/m	64.2 ± 3.7	67.8 ± 2.5	55.5 ± 2.0a	58.6 ± 0.9a	ns	<0.001	ns
Epididymal fat pad weight/TL, g/m	110 ± 10	260 ± 24b	54.1 ± 5.5a	181 ± 19ab	<0.001	<0.001	ns
Gastrocnemius weight/TL, g/m	118 ± 6	127 ± 4	104 ± 4a	121 ± 2b	0.002	0.020	ns
Soleus weight/TL, g/m	8.49 ± 0.52	9.66 ± 0.33	8.55 ± 0.48	8.53 ± 0.31	ns	ns	ns
Brain weight/TL, g/m	42.7 ± 1.4	46.6 ± 0.5 b	43.6 ± 0.7	44.8 ± 1.1	0.015	ns	ns

Values are means ± SE; n = 8–10/group. HCR, high-capacity runners; LCR, low-capacity runners; nd, not determined; ns, nonsignificant; TL, tibia length. ^asignificantly different vs. sedentary animals of the same line; ^bsignificantly different vs. HCR with the same treatment.