title: High-impact exercise strengthens bone in osteopenic ovariectomized rats with the same outcome as Sham rats.
abstract: The effect of jump exercise on middle-aged osteopenic rats was investigated. Forty-two 9-mo-old female rats were either sham-operated (Sham) or ovariectomized (OVX). Three months after surgery, the rats were divided into the following groups: Sham sedentary, Sham exercised, OVX sedentary, and OVX exercised. Rats in the exercise groups jumped 10 times/day, 5 days/wk, for 8 wk, with a jumping height of 40 cm. Less than 1 min was required for the jump training. After the experiment, the right tibia and femur were dissected, and blood was obtained from each rat. OVX rats were observed to have increased body weights and decreased bone mass in their tibiae and femurs. Jump-exercised rats, on the other hand, had significantly increased tibial bone mass, strength, and cortical areas. The bone mass and strength of OVX exercised rats increased to approximately the same extent as Sham exercised rats, despite estrogen deficiency or osteopenia. Our data suggest that jump exercise has beneficial effects on lower limb bone mass, strength, bone mineral density, and morphometry in middle-aged osteopenic rats, as well as in Sham rats.
authors.affiliation: School of Health and Sport Sciences, Chukyo University, Toyota, Aichi 470-0393, Japan. akiko@seiken. sass.chukyo-u.ac.jp
authors.forename: Akiko
authors.initials: A
authors.lastname: Honda
authors.forename: Naota
authors.initials: N
authors.lastname: Sogo
authors.forename: Seigo
authors.initials: S
authors.lastname: Nagasawa
authors.forename: Takuya
authors.initials: T
authors.lastname: Shimizu
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Umemura
mesh_terms: D000818:Animals; D015415:Biomarkers; D001835:Body Weight / Q000502:physiology; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000473:pathology*; D001842:Bone and Bones / Q000033:anatomy & histology / Q000502:physiology*; D005260:Female; D020249:Hormone Replacement Therapy; D009929:Organ Size / Q000502:physiology; D015675:Osteocalcin / Q000097:blood; D010052:Ovariectomy; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013977:Tibia / Q000033:anatomy & histology / Q000502:physiology; D014599:Uterus / Q000502:physiology
chemical_list: D015415:Biomarkers; D015675:Osteocalcin