(Press-News.org) Taking calcium and vitamin D before exercise may influence how bones adapt to exercise, according to a new study. The results will be presented on Tuesday at The Endocrine Society's 95th Annual Meeting in San Francisco.
"The timing of calcium supplementation, and not just the amount of supplementation, may be an important factor in how the skeleton adapts to exercise training," said study lead author Vanessa D. Sherk, PhD, postdoctoral research fellow at the University of Colorado Anschutz Medical Campus. "Further research, however, is needed to determine whether the timing of calcium supplementation affects the skeletal adaptations to exercise training."
Previous research has shown that a year of intense training is associated with substantial decreases in bone mineral density among competitive road cyclists. Experts believe that this kind of exercise-induced bone loss could be related to the loss of calcium during exercise. As blood calcium levels drop, the parathyroid gland produces excess parathyroid hormone, which can mobilize calcium from the skeleton.
In this study, investigators found that an exercise-induced decrease in blood calcium occurred whether calcium supplements were taken before or after exercising. Pre-exercise supplementation, however, resulted in less of a decrease. Although not statistically significant, parathyroid hormone levels increased slightly less among cyclists who took calcium before exercising.
"These findings are relevant to individuals who engage in vigorous exercise and may lose a substantial amount of calcium through sweating," Sherk said. "Taking calcium before exercise may help keep blood levels more stable during exercise, compared to taking the supplement afterwards, but we do not yet know the long-term effects of this on bone density."
The timing of calcium supplementation did not cause a difference in blood levels of a compound that is a biological indicator of bone loss. Both the before- and after-exercise groups exhibited 50-percent increases in the level of this compound, called CTX, for collagen type-1 C-telopeptide.
Study participants included 52 men aged 18 to 45 years. Investigators randomly assigned participants to take 1,000 milligrams of calcium and 1,000 international units of vitamin D either 30 minutes before or one hour after exercise. The exercise comprised a simulated 35-kilometer time trial, and participants wore skin patches to absorb sweat.
Investigators measured blood levels of calcium and parathyroid hormone before and immediately after exercise. They also measured CTX before and 30 minutes after exercise. They used pre- and post-body weight, adjusted for fluid intake, combined with the calcium measured in the sweat from the skin patches, to estimate the amount of calcium lost through the skin during exercise.
###
The National Institutes of Health and the American College of Sports Medicine funded the study.
Timing of calcium and vitamin D supplementation may affect how bone adapts to exercise
2013-06-18
ELSE PRESS RELEASES FROM THIS DATE:
New risk score could lead to earlier prevention of type 2 diabetes in African Americans
2013-06-18
Researchers have developed a risk assessment scoring system that they believe may better identify certain adults-– especially African Americans-– at high risk of developing type 2 diabetes, heart disease and stroke than does the current system of diagnosing the metabolic syndrome. The results will be presented Tuesday at The Endocrine Society's 95th Annual Meeting in San Francisco.
"We have found that the metabolic syndrome manifests differently between males and females and among various racial-ethnic groups," said study co-author Mark DeBoer, MD, associate professor ...
Insulin degludec lowers risk of recurrent low blood sugar or has similar risk to insulin glargine
2013-06-18
Insulin degludec (Tresiba), a new ultra-long-acting insulin, has a similar or reduced risk of recurrent hypoglycemia-- low blood sugar-- compared with the commercially available insulin glargine, a new meta-analysis study finds. Results of the combined analysis, of five completed clinical trials, will be presented Tuesday at The Endocrine Society's 95th Annual Meeting in San Francisco.
The studies included nearly 3,400 adults with type 2 diabetes who had a daily injection of either insulin degludec or glargine combined with either a mealtime insulin or oral diabetic medications. ...
Stone Age technological and cultural innovation accelerated by climate
2013-06-18
Archaeological and genetic evidence suggests that modern humans (the modern form of Homo sapiens, our species) originated in Africa during the Stone Age, between 30,000 and 280,000 years ago. The latest archaeological excavations in southern Africa have shown that technological innovation, linked to the emergence of culture and modern behaviour, took place abruptly: the beginnings of symbolic expression, the making of tools from stone and bone, jewellery or the first agricultural settlements.
An international team of researchers has linked these pulses of innovation to ...
Scientists find potential genetic drivers behind male heart disease risk
2013-06-18
University of Leicester scientists have discovered a potential genetic contributor to the increased risk of heart disease among men.
A team of researchers including clinicians and scientists have made an important step forward in search of the mechanisms underlying increased risk of coronary artery disease in men who carry a particular type of the Y chromosome (haplogroup I).
The team, from the University's Department of Cardiovascular Sciences and Department of Health Sciences, have followed up their recent award-winning study showing that men with haplogroup I of ...
Seismic gap outside of Istanbul
2013-06-18
Earthquake researchers have now identified a 30 kilometers long and ten kilometers deep area along the North Anatolian fault zone just south of Istanbul that could be the starting point for a strong earthquake. The group of seismologists including Professor Marco Bohnhoff of the GFZ German Research Centre for Geosciences reported in the current online issue of the scientific journal Nature (Nature Communications, DOI: 10.1038/ncomms2999) that this potential earthquake source is only 15 to 20 kilometers from the historic city center of Istanbul.
The Istanbul-Marmara region ...
The secret of DNA methylation
2013-06-18
Methylation refers to a chemical modification of DNA and this modification can occur in millions of positions in the DNA sequence. Until now, scientists believed that this epigenetic phenomenon actively reduced the expression of certain genes. Today, a team of researchers from the University of Geneva (UNIGE), Switzerland, led by Emmanouil Dermitzakis, Louis-Jeantet Professor at the Faculty of Medicine, reveals that this is not always the case and that DNA methylation may play both a passive and active role in gene regulation. The mechanistic relationships between DNA sequence ...
Pioneering breakthrough of chemical nanoengineering to design drugs controlled by light
2013-06-18
The scientific cooperation between chemists, biotechnologists and physicists from various Catalan institutes, headed by Pau Gorostiza, from the Institute for Bioengineering of Catalonia (IBEC), and Ernest Giralt, from the Institute for Research in Biomedicine (IRB Barcelona), has led to a breakthrough that will favor the development of light-regulated therapeutic molecules. The breakthrough published online today in the German journal of reference in chemistry Angewandte Chemie has received recognition as a "Very Important Paper", a distinction that only 5% of the articles ...
Feline behavior experts release guidelines to improve the welfare of cats
2013-06-18
LA, London (18 June 2013). A team of internationally recognized feline experts including veterinarians and feline scientists co-chaired by Dr Sarah Ellis from the University of Lincoln, U.K. and Dr Ilona Rodan, Director of Cat Care Clinic, Wisconsin, U.S.A. were invited by the International Society of Feline Medicine (ISFM) and the American Association of Feline Practitioners (AAFP) to compile guidelines for veterinarians, owners and those working with cats on how to meet the environmental needs of the domestic cat. The new guidelines appear in the Journal of Feline Medicine ...
Rice blast research reveals details on how a fungus invades plants
2013-06-18
Like a stealthy enemy, blast disease invades rice crops around the world, killing plants and cutting production of one of the most important global food sources. Now a study by an international team of researchers has shed light on how the rice blast fungus, Magnaporthe oryzae, invades plant tissue. The finding is a step towards learning how to control the disease, which by some estimates destroys enough rice to feed 60 million people annually.
The team, from the Halpin Laboratory at the University of Exeter, in collaboration with Kansas State University and the Iwate ...
It's the way you tell em': Study discovers how the brain controls accents and impersonations
2013-06-18
A study, led by Royal Holloway University researcher Carolyn McGettigan, has identified the brain regions and interactions involved in impersonations and accents.
Using an fMRI scanner, the team asked participants, all non-professional impressionists, to repeatedly recite the opening lines of a familiar nursery rhyme either with their normal voice, by impersonating individuals, or by impersonating regional and foreign accents of English.
They found that when a voice is deliberately changed, it brings the left anterior insula and inferior frontal gyrus (LIFG) of the ...