TY - JOUR
T1 - The effects of a calcium-rich pre-exercise meal on biomarkers of calcium homeostasis in competitive female cyclists: a randomised crossover trial
AU - Haakonssen, Eric C
AU - Ross, Megan L
AU - Knight, Emma J
AU - Cato, Louise E
AU - Nana, Alisa
AU - Wluka, Anita Estelle
AU - Cicuttini, Flavia Maria
AU - Wang, Bing Hui
AU - Jenkins, David G
AU - Burke, Louise Mary
PY - 2015
Y1 - 2015
N2 - Cycling is recognised as a sport in which there is a high incidence of poor bone health. Sweat calcium losses may contribute to this. Purpose: To examine whether a calcium-rich pre-exercise meal attenuates exercise-induced perturbations of bone calcium homeostasis caused by maintenance of sweat calcium losses. Methods: Using a randomized, counterbalanced crossover design, 32 well-trained female cyclists completed two 90 min cycling trials separated by 1 day. Exercise trials were preceded 2 hours by either a calcium-rich (1352 ? 53 mg calcium) dairy based meal (CAL) or a control meal (CON; 46 ? 7 mg calcium). Blood was sampled pre-trial; pre-exercise; and immediately, 40 min, 100 min and 190 min post-exercise. Blood was analysed for ionized calcium and biomarkers of bone resorption (Cross Linked C-Telopeptide of Type I Collagen (CTX-I), Cross Linked C-Telopeptide of Type II Collagen (CTX-II), Parathyroid Hormone (PTH), and bone formation (Procollagen I N-Terminal Propeptide (PINP)) using the established enzyme-linked immunosorbent assay technique. Results: PTH and CTX-I increased from pre-exercise to post-exercise in both conditions but was attenuated in CAL (p <0.001). PTH was 1.55 [1.20, 2.01] times lower in CAL immediately post-exercise and 1.45 [1.12, 1.88] times lower at 40 min post-exercise. CTX-I was 1.40 [1.15, 1.70] times lower in CAL at immediately post-exercise, 1.30 [1.07, 1.57] times lower at 40 min post-exercise and 1.22 [1.00, 1.48] times lower at 190 min post-exercise (p <0.05). There was no significant interaction between pre-exercise meal condition and time point for CTX-II (p = 0.732) or PINP (p = 0.819). Conclusion: This study showed that a calcium-rich pre-exercise breakfast meal containing 1350 mg of calcium consumed 90 min before a prolonged and high intensity bout of stationary cycling attenuates the exercise induced rise in markers of bone resorption - PTH and CTX-I.
AB - Cycling is recognised as a sport in which there is a high incidence of poor bone health. Sweat calcium losses may contribute to this. Purpose: To examine whether a calcium-rich pre-exercise meal attenuates exercise-induced perturbations of bone calcium homeostasis caused by maintenance of sweat calcium losses. Methods: Using a randomized, counterbalanced crossover design, 32 well-trained female cyclists completed two 90 min cycling trials separated by 1 day. Exercise trials were preceded 2 hours by either a calcium-rich (1352 ? 53 mg calcium) dairy based meal (CAL) or a control meal (CON; 46 ? 7 mg calcium). Blood was sampled pre-trial; pre-exercise; and immediately, 40 min, 100 min and 190 min post-exercise. Blood was analysed for ionized calcium and biomarkers of bone resorption (Cross Linked C-Telopeptide of Type I Collagen (CTX-I), Cross Linked C-Telopeptide of Type II Collagen (CTX-II), Parathyroid Hormone (PTH), and bone formation (Procollagen I N-Terminal Propeptide (PINP)) using the established enzyme-linked immunosorbent assay technique. Results: PTH and CTX-I increased from pre-exercise to post-exercise in both conditions but was attenuated in CAL (p <0.001). PTH was 1.55 [1.20, 2.01] times lower in CAL immediately post-exercise and 1.45 [1.12, 1.88] times lower at 40 min post-exercise. CTX-I was 1.40 [1.15, 1.70] times lower in CAL at immediately post-exercise, 1.30 [1.07, 1.57] times lower at 40 min post-exercise and 1.22 [1.00, 1.48] times lower at 190 min post-exercise (p <0.05). There was no significant interaction between pre-exercise meal condition and time point for CTX-II (p = 0.732) or PINP (p = 0.819). Conclusion: This study showed that a calcium-rich pre-exercise breakfast meal containing 1350 mg of calcium consumed 90 min before a prolonged and high intensity bout of stationary cycling attenuates the exercise induced rise in markers of bone resorption - PTH and CTX-I.
UR - http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4430171/pdf/pone.0123302.pdf
U2 - 10.1371/journal.pone.0123302
DO - 10.1371/journal.pone.0123302
M3 - Article
SN - 1932-6203
VL - 10
JO - PLoS ONE
JF - PLoS ONE
IS - 5
M1 - e0123302
ER -