Road cycling and bone health: a scoping review

Introduction
In competitive road cycling, low body mass is a common focus for many athletes. Due to the high energy expenditure and non-weight bearing nature of competitive road cycling, there are associated health risks including relative energy deficiency and low bone mineral density. Untreated, this can lead to an increased susceptibility to fracture. This can be a particular problem in competitive road cycling where the prevalence of falls is high.
Methods
A scientific literature search on studies investigating relative energy deficiency and bone mineral density in the sport of road cycling was performed.
Results
Twenty-four studies investigated the relationship between road cycling and relative energy deficiency, bone mineral density, bone structure, calcium and vitamin D, markers for bone metabolism and strength training. Road cyclists were generally found to be at risk of relative energy deficiency and reduced bone mineral density. However, bone strength indices on peripheral quantitative computed tomography were not reduced. There was also conflicting evidence on the effect of consuming calcium and vitamin D on markers for bone metabolism and bone mineral density. Studies supported evidence that the inclusion of strength training can have a positive effect on bone mineral density in road cyclists.
Discussion
Relative energy deficiency in road cyclists is particularly concerning due to its detrimental impact on bone health and general increased risk of injury. Similarly, low bone mineral density is worrying due to high prevalence of falls and subsequent fracture risk. While it remains to be seen whether calcium and vitamin D supplementation provide adequate bone protection, increased education among competitive road cyclists on the benefits of energy balance and strength training in terms of bone health could be useful and should be advocated by their support team.
Conclusion
There was evidence of increased risk of relative energy deficiency, low bone mineral density and increased bone resorption in road cyclists. However, there was also evidence that strength and impact training could improve bone health in competitive road cyclists.