کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2779429 | 1153273 | 2012 | 10 صفحه PDF | دانلود رایگان |
Individuals often perform exercise in the fasted state, but the effects on bone metabolism are not currently known. We compared the effect of an overnight fast with feeding a mixed meal on the bone metabolic response to treadmill running. Ten, physically‐active males aged 28 ± 4 y (mean ± SD) completed two, counterbalanced, 8 d trials. After 3 d on a standardised diet, participants performed 60 min of treadmill running at 65% VO2max on Day 4 following an overnight fast (FAST) or a standardised breakfast (FED). Blood samples were collected at baseline, before and during exercise, for 3 h after exercise, and on four consecutive follow-up days (FU1–FU4). Plasma/serum were analysed for the c-terminal telopeptide region of collagen type 1 (β‐CTX), n-terminal propeptides of procollagen type 1 (P1NP), osteocalcin (OC), bone alkaline phosphatase (bone ALP), parathyroid hormone (PTH), albumin-adjusted calcium, phosphate, osteoprotegerin (OPG), cortisol, leptin and ghrelin. Only the β-CTX response was significantly affected by feeding. Pre‐exercise concentrations decreased more in FED compared with FAST (47% vs 26%, P < 0.001) but increased during exercise in both groups and were not significantly different from baseline at 1 h post‐exercise. At 3 h post‐exercise, concentrations were decreased (33%, P < 0.001) from baseline in FAST and significantly lower (P < 0.001) than in FED. P1NP and PTH increased, and OC decreased during exercise. Bone markers were not significantly different from baseline on FU1–FU4. Fasting had only a minor effect on the bone metabolic response to subsequent acute, endurance exercise, reducing the duration of the increase in β-CTX during early recovery, but having no effect on changes in bone formation markers. The reduced duration of the β-CTX response with fasting was not fully explained by changes in PTH, OPG, leptin or ghrelin.
► Prior to exercise, feeding decreased β-CTX compared with fasting, but exercise increased concentrations in both groups to a similar level.
► Fasting reduced the duration of the exercise-associated increase in β-CTX, with lower concentrations at 3 h post-exercise compared with feeding.
► P1NP increased and OC decreased during exercise, but neither response was affected by feeding.
► Changes in PTH, OPG, leptin and ghrelin with exercise were all unaffected by feeding.
► All bone markers were not significantly different from baseline at 1–4 days post-exercise.
Journal: Bone - Volume 51, Issue 6, December 2012, Pages 990–999