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The Impact of Caloric Restriction and Resistance Training on Bone Mineral Density and Bone Strength in Growing Male Rats
Author(s) -
Slater Brady,
Lee Kassandra,
Folta Haley,
Wong Quinton,
Gettleman Brandon,
Hernandez John,
Prakash Anu,
Jaque S Victoria,
Sumida Ken D
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.1242.1
Subject(s) - bone mineral , caloric theory , medicine , resistance training , endocrinology , body weight , zoology , strength training , osteoporosis , physical therapy , biology
The purpose of this study was to examine the impact of caloric restriction and resistance training on bone mineral density (BMD, in g/cm2, measured via DXA) and bone strength (Fmax, in Newtons, measured via 3 pt bending rig) of the tibia in growing male rats. 32 male rats (initially 8 wks old) were randomly divided into: a non‐exercised ad libitum fed Control group (C, n=8) pair fed with a non‐exercised group fed a 20% caloric restrictive diet (D, n=8), and an exercised ad libitum fed group (RT, n=8) pair fed with an exercised group fed a 20% caloric restrictive diet (DT, n=8). The exercise groups were conditioned to climb a 1 meter vertical ladder 4X per session with weights appended to their tail 3 days/wk for 6 wks. All exercised animals initially carried 30% of their body weight (BW) and progressed to 150% BW by week 6. After 6 wks, the body weight was significantly lower for diet fed animals (383.8 ± 6.8 g) compared to ad libitum fed animals (459.9 ± 9.3 g). There were no interaction effects (exercise x diet) for BMD or bone strength. The main effect of exercise on BMD was significantly greater ( P = 0.047) for trained groups (RT and DT = 0.215 ± 0.002) compared to non‐exercised groups (C and D = 0.206 ± 0.002) whereas the main effect of diet on BMD was not statistically significant ( P = 0.086) for ad libitum fed groups (C and RT = 0.214 ± 0.004) compared to diet fed groups (D and DT = 0.207 ± 0.002). The main effect of exercise on Fmax was significantly greater ( P = 0.001) for exercised groups (RT and DT = 139.5 ± 5.1) compared to non‐exercised groups (C and D = 118.7 ± 3.8) and the main effect of diet on Fmax was significantly greater ( P = 0.001) for ad libitum fed groups (C and RT = 138.8 ± 5.3) compared to diet fed groups (D and DT = 119.4 ± 3.8). The results indicate that during growth, resistance training elevated BMD and bone strength whereas a 20% caloric restrictive diet lowered bone strength in the absence of a decline in BMD. Support or Funding Information Chapman University Faculty Research Grant