Table 3.

Pre- to post-bed rest change in regional bone densities (DEXA)

Region	Treatment	Pre-BR (g/cm2)	Post-BR (g/cm2)
Total body	CON	1.100 ± 0.056	1.103 ± 0.047
	EX	1.099 ± 0.079	1.098± 0.075
Legs	CON	1.131 ± 0.069	1.126 ± 0.065
	EX	1.129 ± 0.103	1.123 ± 0.098
Femoral neck	CON	0.967 ± 0.123	0.966 ± 0.115
	EX	0.956 ± 0.153	0.975 ± 0.159
Femoral shaft*	CON	1.126 ± 0.063	1.103 ± 0.068
	EX	1.108 ± 0.154	1.113 ± 0.153
Total hip*	CON	0.976 ± 0.058	0.960 ± 0.061
	EX	0.968 ± 0.122	0.971 ± 0.121

Subjects were identical twins assigned at random to sedentary bed rest (CON) or bed rest combined with lower body negative pressure treadmill exercise (EX). Data are means ± SD for 7 subjects per group.

^*Significant interaction (P < 0.01) between treatment and time, with bone density being lower after bed rest (BR) in the CON group but with no change in bone density after BR in the EX group.