SIX WEEKS OF TREADMILL RUNNING EXERCISE IMPROVE BONE ARCHITECTURE IN ADULT OSTEOPENIC RATS: AN EXPERIMENTAL STUDY TOWARD EXERCISE DOSE PRESCRIPTION

Abstract

Question: Can exercise dose be established for bone weakness treatment? Design: Randomized experimental study. Participants: Thirty two adult (12 weeks) Wistar rats (16 males and 16 females) weighed [Formula: see text][Formula: see text]gm. Intervention: Rats were tail suspended for 2 weeks and then randomly divided into four groups; Group I ([Formula: see text]) sacrificed after suspension, Group II ([Formula: see text]) normal cage activities. Group III: ([Formula: see text]) level surface treadmill running. Group IV: ([Formula: see text]) uphill treadmill at angle of 15∘. The running speed was 12[Formula: see text]m/min for a period of 30[Formula: see text]min daily at frequency of 5 days/week for 6 weeks. Outcome measures: Histomorphometric analysis of distal femurs of right hind limbs to measure bone architectural parameters (cortical thickness, Tb.Th, Tb.Nm, Tb.Sp, Tb.Ar, Bone marrow area and density and TBA). Results: Significant improvements were shown in bone architecture in distal femur of Group IV ([Formula: see text]) compared to both Group I and Group II. No significant improvement in distal femur in Group III ([Formula: see text]) compared to both Group I and Group II. The percentage of change was found to be 62–96% between Group IV and Group II and 72– 82% between Group IV and Group I. Conclusion: The results suggested that uphill treadmill running exercises were effective to induce changes in bone tissue in the form of changing trabecular dimensions and density. The induced structural improvement was site specific and dose dependent.