2017 年 63 巻 3 号 p. 186-194
Objective: This study clarified bone turnover at different training intensities based on the annual schedule of a male college artistic gymnastics club.
Methods: For 21 male college artistic gymnasts, bone metabolism markers (bone alkaline phosphatase (BAP), intact procollagen type 1 N-terminal propeptide (P1NP), bone-specific tartrate-resistant acid phosphatase 5b (TRACP-5b), type I collagen crosslinked N-telopeptide in serum (s-NTX), type I collagen crosslinked N-telopeptide in urine (u-NTX)) were measured during three periods: pre-season, with gradually increasing training intensity at the beginning of a competition; competition, when gymnasts compete and train at the highest strength; and training, with lower intensity training after competition. Gymnasts train by practicing their techniques.
Results: Procollagen type 1 N-terminal propeptide, a bone formation marker, showed significantly higher concentration during the competition period (129.4±50.7 μg/l) than during the training period (116.8±47.2 μg/l)(p<0.01). Also, bone-specific tartrate-resistant acid phosphatase 5b, a bone resorption marker, showed significantly higher concentration during the pre-season (677.2±218.8 mU/dl) and training periods (743.2±231.9 mU/dl) than during the competition period (577.0±203.0 mU/dl)(p<0.01). Moreover, concentrations were higher during the training period (743.2±231.9 mU/dl) than during the pre-season period (677.2±218.8 mU/dl)(p<0.05). Results of BAP and s-NTX respectively resembled those of P1NP and TRACP-5b. No significant change was observed in u-NTX.
Conclusion: Bone metabolism marker results suggest that bone formation is dominant when training intensity is higher and strong mechanical stress is placed on bones. Bone resorption is dominant when training intensity is lower and less mechanical stress is placed on bones.
