Endurance training and bone metabolism in middle-aged rats.
This study was performed to observe the influence of moderate treadmill running on bone of middle-aged male rats. Seventy 15-month-old Wistar rats were used. Ten initial controls (IC) were killed on day 0. Among the 60 others, three groups of ten exercised rats (E) run 1 h/day, 6 days/week at 60% of their maximum aerobic capacity. On days 30, 60 and 90 of the training period, 20 rats, ten E and ten R (resting animals), were killed. Femoral failure stress never varied and was never different in E and R during the experiment. On day 90 whole body mineral content and mineral density were higher in E than R. Simultaneously, total, diaphyseal and metaphyseal femoral densities were lower in R than IC or than in E. No difference was observed between IC and E. In resting rats, urinary deoxypyridinoline excretion (a marker of bone resorption) increased between days 0 and 90, while it did not change in runners. These results indicate that in middle-aged rats, moderate running prevents decrease in bone mineral density, probably by inhibiting bone resorption.
Davicco
M J
MJ
Métabolisme Minéral, UMMM, INRA Clermont-Theix, Ceyrat, France.
Horcajada-Molteni
M N
MN
Gaumet-Meunier
N
N
Lebecque
P
P
Coxam
V
V
Barlet
J P
JP
D000375:Aging / Q000097:blood / Q000378:metabolism* / Q000652:urine; D000596:Amino Acids / Q000652:urine; D000818:Animals; D001842:Bone and Bones / Q000378:metabolism*; D005269:Femur; D008297:Male; D009929:Organ Size; D015675:Osteocalcin / Q000097:blood; D010805:Physical Conditioning, Animal; D051381:Rats; D017208:Rats, Wistar; D012420:Running
D000596:Amino Acids; D015675:Osteocalcin; C036020:deoxypyridinoline