Effects of a high calcium pre-event meal on biomarkers of calcium homeostasis in female cyclists

The effects of a calcium-rich pre-exercise meal on 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) in competitive female cyclists.

Status

Completed

Phases

Unknown

Study type

Interventional

Source

ANZCTR

Registry ID

ACTRN12614000675628

Enrollment

Registered

2014-06-26

Start date

2013-05-01

Completion date

2013-05-13

Last updated

2020-01-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

Brief summary

Background: An issue of high importance to the AIS is the prevention/treatment of low bone density in athletes: low bone mineral density (BMD) is common in both male and female cyclists. This may be because of a lack of weight-bearing activity, menstrual disturbances, and low energy availability due to weight loss practices or the high energy expenditure. An additional risk factor of interest is the acute effect of sweat calcium loss. These sweat calcium losses during prolonged exercise may cause a significant decline in blood calcium concentrations during training. The body protects blood calcium levels by stimulating the bones to release calcium into the blood to restore levels, and increasing bone re-absorption. Purpose: to determine whether a high calcium pre-event meal can reduce levels of hormones that are responsible for increasing bone resorption. Hypothesis: based on previous findings involving calcium-fortified water, it is hypothesised that a calcium-rich dairy based meal will reduce the exercise induced rise in biomarkers of bone resorption observed during cycling.

Interventions

Cyclists completed two 90 min cycling trials (80 min at 60% maximal aerobic power followed by a 10 min maximal time trial) separated by 1 day. Exercise trials were preceded 2 h by either a calcium-rich (mean +/- SD; 1352 +/- 53 mg calcium) dairy based meal or a control meal (46 +/- 7 mg calcium). The calcium-rich meal consisted of rolled-oats cooked with calcium-fortified (Tricalcium phosphate, Nano-calcium) milk, yoghurt and additional milk.

Study design

Allocation

Non-randomised trial

Intervention model

Crossover

Primary purpose

Prevention

Masking

Open (masking not used)

Eligibility

Sex/Gender

All

Age

17 Years to 32 Years

Healthy volunteers

Yes

Inclusion criteria

Aged 17 to 32 y; greater than or equal to 18 mo cycling racing experience; able to commit to a 10 d camp based at the Australian Institute in Canberra.

Exclusion criteria

Exclusion criteria were vitamin D deficiency (25-OH Vitamin D < 30 ng/mL), thyroid dysfunction (n=1), liver or kidney dysfunction, regular use of medications or supplements known to affect bone or calcium metabolism or thyroid function (e.g., thiazide diuretics, bisphosphonates, oral steroids).

Outcome results