Meeting Abstract
Distance runners with similar abilities on level terrain often differ significantly in their ability to run on inclines. This study investigates the causes of these interindividual differences in relative incline running ability. Performance determining factors such as mass specific leg muscle strength and running kinematics are likely to affect uphill and level running differentially. As most of the work to raise the center of mass on inclines is done at the hip joint, the strength of the hip retractor muscles might be correlated with incline running performance. Since heart and metabolic rates are tightly correlated within each individual, runners with less efficient incline running kinematics should have greater increases in heart rate when running uphill. In this study 30 subjects performed incremental treadmill runs to exhaustion at 0° and 10° inclines. The treadmill was started at 2.2ms-1 and 1.8ms-1 for the level and incline trials respectively. Speed was increased by 0.09ms-1 at the end of each minute until subjects could no longer maintain the pace. Relative incline running ability was taken as the ratio of the incline: level distance covered. Subjects’ heart rates were measured throughout the trials and their stride kinematics were tracked with a motion capture system. The strengths of their hamstring and quadriceps muscle groups were measured by having them use their legs to pull isometrically on a rope attached to a strain gage. Subjects ran 3.8±1.6 and 1.6±1.0 km in incline and level trials respectively. Incline to level distance ratios ranged from 0.25 to 0.56. Relatively better incline runners tended to have lower incline: level heart rate ratios and to have a higher ratio of hamstring to quadriceps muscle strength. Runners may be able to improve their performance on inclines by strengthening their hamstring muscles and increasing their efficiency by modifying their gait kinematics.
