Summary

This study will address the important problem of musculoskeletal injuries caused by high intensity exercise during training and racing in young racehorses. In particular this study will examine the effect of different levels of high speed galloping on microdamage accumulation, modelling and remodelling during early training. These processes appear to be critically important in both the adaptive response of bone to loading as well as the development on bone fatigue injury. However the timing and magnitude of microdamage formation, bone resorption and new bone formation in response to the initiation of high intensity training has not been well characterised. The aim of this study is to determine what type of loading pattern during early training induces the bone adaptive response is most likely to resist fatigue injury. This data will also provide valuable insights into the molecular and cellular activities that occur during early bone remodelling in response to training. This information can be used to incorporate training strategies that reduce injury in 2 and 3 year old racehorses while still allowing horses to gain fitness and adapt their musculoskeletal system to the rigors of racing.

Program

Thoroughbred Horses

Research Organisation

The University of Queensland

Objective Summary

1. Develop a minimally-invasive bone biopsy technique to examine the response of bone to exercise in a highly controlled manner in experimental animals.
2. To use quantitative PCR, dynamic histomorphometry, μCT and specialised bone histology techniques to characterise the early molecular, cellular and mechanical responses of bone to high intensity exercise.
3. To determine to what extent bone remodelling is increased or decreased during high intensity training.
4. To determine if the bone microdamage burden is increased during early training and if this microdamage is involved in the initiation of an excessive remodelling response.
5. To determine what changes occur in the fatigue and remodelling response of bone to variations in the intensity, frequency and duration of exercise.