Effect of Fasting Versus Feeding on the Bone Metabolic Response to Running

Effect of Fasting Versus Feeding on the Bone Metabolic Response to Running

This study examined changes in bone metabolism (markers of bone turnover, calcium metabolism) with a bout of acute treadmill running preceded by either a single, mixed meal or an overnight fast.

Ten physically active males aged 28 ± 4 y (mean ± 1SD) 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 exercise, during exercise, for 3h after exercise and on four consecutive follow-up days (FU1-FU4). Plasma/serum were analysed for β CTX, P1NP, OC, bone ALP, PTH, ACa, PO4, OPG, cortisol, leptin and ghrelin.

Inclusion Criteria:

• history of weight bearing exercise
• fasting vitamin D concentration of >30 nmol•L-1 and/or a fasting parathyroid hormone (PTH) concentration of <6.9 pmol•L-1.

Exclusion Criteria:

• smokers
• suffered a bone fracture in the previous 12 months
• musculoskeletal injury
• condition/medication known to affect bone metabolism