Journal of Bone and Mineral Metabolism

, Volume 23, Issue 4, pp 289–294

How many days per week should rats undergo running exercise to increase BMD?

  • Yoshinobu Hagihara
  • Satoshi Fukuda
  • Sumio Goto
  • Haruzo Iida
  • Masashi Yamazaki
  • Hideshige Moriya
ORIGINAL ARTICLE

DOI: 10.1007/s00774-005-0601-z

Cite this article as:
Hagihara, Y., Fukuda, S., Goto, S. et al. J Bone Miner Metab (2005) 23: 289. doi:10.1007/s00774-005-0601-z

Abstract

The aim of the present study was to examine the effect of different frequencies of running exercise on increasing bone mineral density (BMD) and improving bone histomorphology at various sites of the skeleton (tibia, femur, and second lumbar vertebra) in young rats. Twenty-five female Wistar rats, 8 weeks old, were divided into five groups, of 5 animals each according to running load: control group, no running (A group); running load (RL), 4 days per week (d/w; B group); RL, 5 d/w (C group); RL, 6 d/w (D group); and RL, 7 d/w (E group). Rats ran on a treadmill at a speed of 15 m/min for 30 min per day over an 8-week period. The results indicated that the BMD of the tibia in the B, C, D, and E groups and that of the femur in the B and E groups increased significantly over that of the A group. However, the cortical BMD and trabecular BMD of the second lumbar vertebra did not change. In regard to bone histomorphometry of the tibia, a parameter of bone resorption (eroded surface/bone surface) was significantly lower in the B and D groups than in the A group. There were no differences in the parameters of bone formation. Tartaric acid-resistant acid phosphatase (TRACP) values were significantly lower in the B and C groups than in the A group. There were significant increases in body weight in the B group and in muscle weight in the C group. From the data obtained in this study, it was concluded that increases in BMD were obtained by a moderate running load at frequencies of 4 and 5 days per week.

Key words

Running exerciseRatTreadmillBone mineral densityBone resorption

Copyright information

© Springer-Verlag Tokyo 2005

Authors and Affiliations

  • Yoshinobu Hagihara
    • 1
  • Satoshi Fukuda
    • 2
  • Sumio Goto
    • 3
  • Haruzo Iida
    • 2
  • Masashi Yamazaki
    • 4
  • Hideshige Moriya
    • 4
  1. 1.Department of Orthopedic SurgeryJyoto Insurance HospitalTokyoJapan
  2. 2.International Space Radiation LaboratoryNational Institute of Radiological SciencesChibaJapan
  3. 3.Department of Orthopedic SurgeryNational Center of Neurology and PsychiatryIchikawaJapan
  4. 4.Department of Orthopedic SurgeryChiba University of MedicineChibaJapan