Effect of impact exercise on bone metabolism.
CONCLUSIONS
Regular impact exercise in premenopausal women caused positive osteogenic effects associated to low basal serum parathormone (PTH) but had no effects on bone turnover markers PINP or TRACP5b. The low serum basal PTH levels during impact exercise may be a sign of increased incorporation of calcium to bone.


BACKGROUND
This study aimed to determine the long-term effects of high-impact exercise on bone turnover and calciotropic hormones.


METHODS
We performed a 12-month population-based, randomized, controlled exercise trial in 120 women (age 35-40 years) randomly assigned to an exercise group (EG; n = 60) or a control group (CG; n = 60). The exercise regimen consisted of supervised high-impact exercises three times per week. Daily impact loading was assessed by using an accelerometer. Bone turnover markers and calciotropic hormones were analyzed at 0, 6, and 12 months.


RESULTS
Twelve months of impact exercise did not reveal any treatment effects in bone turnover markers PINP or TRAPC5b, whereas serum basal PTH decreased significantly more in the EG than in the CG (-11.2 vs. -2.2 pg/mL; p = 0.03). The change in PTH was dose dependent and most clearly seen in subjects with 96 to 130 daily impacts at 2.5 to 5.3 g (e.g., running or jumping).


CONCLUSIONS
Regular impact exercise does not cause persistent alterations in bone turnover emphasizing necessity of continuous training to achieve bone benefits. Impact exercise training lowers the serum basal PTH levels and possibly enables greater difference between the basal PTH and transient exercise-induced PTH peaks leading to osteogenic effects.
Vainionpää
A
A
Department of Medical Technology, Institute of Biomedicine, University of Oulu, Oulu, Finland. aki.vainionpaa@fimnet.fi
Korpelainen
R
R
Väänänen
H K
HK
Haapalahti
J
J
Jämsä
T
T
Leppäluoto
J
J
D000135:Acid Phosphatase / Q000097:blood; D000328:Adult; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000502:physiology; D001842:Bone and Bones / Q000378:metabolism*; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D005269:Femur / Q000502:physiology; D006801:Humans; D007527:Isoenzymes / Q000097:blood; D009043:Motor Activity / Q000502:physiology; D010281:Parathyroid Hormone / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D017697:Premenopause / Q000378:metabolism / Q000502:physiology; D011347:Procollagen / Q000097:blood; D000071681:Tartrate-Resistant Acid Phosphatase; D013977:Tibia / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology
D015415:Biomarkers; D007527:Isoenzymes; D010281:Parathyroid Hormone; D010446:Peptide Fragments; D011347:Procollagen; C047202:procollagen Type I N-terminal peptide; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase