Research has shown that serious cyclists are more susceptible to fractures because of significantly lower bone mineral density than other endurance athletes.
The high-energy demands of competitive cycling may cause an imbalance in the rate of bone formation and bone breakdown in cyclists. This imbalance may contribute to their reduced bone density, although the exact reasons are not yet clearly understood.
The research results will be published in Applied Physiology Nutrition and Metabolism. In the study, racers who matched their energy intake to their energy expenditure, thus maintaining their energy balance, showed increased evidence of bone turnover. The increase in new bone was greater than the loss of bone, leading the researchers to conclude that these were positive effects for bone mass over the long term.
"The findings suggest that participation in stage races might not have negative effects on bone turnover if energy intake matches the energy cost of high-intensity racing over several days," said Pam Hinton, associate professor in the Department of Nutrition and Exercise Physiology. "The results are consistent with the practical recommendation that elite cyclists should match their energy intake to the high energy demands of stage racing."
However, reduced bone formation and increased bone loss due to insufficient energy intake is only one part of the puzzle. Other factors that may influence cyclists’ BMD include low body weight, loss of calcium through sweat and high amounts of time cycling, which is a minimally-weight bearing activity. "This study measured only the short-term effects of stage racing on bone turnover; future studies should assess the long-term effects," Hinton said.