Osteoporosis International

, Volume 20, Issue 6, pp 963–972 | Cite as

Minimum level of jumping exercise required to maintain exercise-induced bone gains in female rats

Original Article

Abstract

Summary

This study determines the minimum level of exercise required to maintain 8 weeks of jumping exercise-induced bone gains in rats. It was found that the minimum level of exercise required for maintaining the different exercise-induced bone gains varied between 11% and 18% of the initial exercise intensity.

Introduction

This study ascertains the minimum level of follow-up exercise required to maintain bone gains induced by an 8-week jumping exercise in rats.

Methods

Twelve groups of 12-week old rats (n = 10 rats per group) were given either no exercise for 8 (8S) or 32 weeks (32S), or received 8 weeks of standard training program (8STP) that consisted of 200 jumps per week, given at 40 jumps per day for 5 days per week, followed by 24 weeks of exercise at loads of either 40 or 20 or 10 jumps per day, for either 5, or 3, or 1 day/week. Bone mass, strength, and morphometric properties were measured in the right tibia. Data were analyzed using one-way analyses of variance.

Results

Bone mass, strength, mid-shaft periosteal perimeter and cortical area were significantly (p < 0.05) higher in the rats given 8STP than that in the 8S group. The minimal level of exercise required to maintain the bone gains was 31, 36, 25, and 21 jumps per week for mass, strength, periosteal perimeter and cortical area, respectively.

Conclusions

Eight weeks of jumping exercise-induced bone gains could be maintained for a period of 24 weeks with follow-up exercise consisting of 11% to 18% of the initial exercise load.

Keyword

Bone maintenance Cortical area Fat free dry weight Jumping exercise Maximum load Periosteal perimeter 

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Copyright information

© International Osteoporosis Foundation and National Osteoporosis Foundation 2008

Authors and Affiliations

  • F. K. Ooi
    • 1
  • R. Singh
    • 1
  • H. J. Singh
    • 2
  • Y. Umemura
    • 3
  1. 1.Sports Science Unit, School of Medical SciencesUniversiti Sains MalaysiaPenangMalaysia
  2. 2.Faculty of MedicineUniversiti Teknologi MARAShah AlamMalaysia
  3. 3.School of Health and Sport SciencesChukyo UniversityToyotaJapan

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