Associations Between 24-Hour Dietary Intake And Biomechanical Changes During A Long Run: An Exploratory Study

Abstract

Both nutrition and biomechanics play important roles for running and athletic performance. However, to date they have usually been studied separately and there is minimal literature evaluating effects of nutritional status or interventions on biomechanical outcomes. PURPOSE: This exploratory study evaluated relationships between nutritional status prior to a long hilly run and changes in running mechanics following the run. METHODS: Eight trail runners (5 M/3 F; weekly mileage: 27.6 ± 8.5 miles) ran a 10-mile hilly run which matched the elevation profile of a popular local trail run. 3D kinematics and ground reaction forces were collected during five-minute level ground running sections prior to and following the run. Changes in spatial temporal parameters, ground reaction forces, and leg stiffness variables from pre to post run were computed for each participant's left leg using Visual3D. Pre-run 24-hour dietary recalls were analyzed for total caloric intake (Tkcal) and percent calories from carbohydrate (%CHO), protein (%PRO), and fat (%FAT). Pearson's correlations were used to asses associations between each nutritional variable and changes in biomechanical variables. RESULTS: There were significant associations between %PRO and changes in peak ground reaction force and changes in contact time such that runners with higher %PRO displayed smaller changes in biomechanics (Figure 1). Similar associations were observed between Tkcal and %FAT and changes in vertical center of mass displacement. CONCLUSIONS: This preliminary study suggests nutritional status prior to a long run may affect the changes in biomechanics a runner experiences during the run. These biomechanical effects have implications for both performance and injury, and highlight the importance of protein for long distance runners. Additional research is required to evaluate whether manipulating nutrition can be used to manage biomechanical changes associated with long duration running.