Biomechanical, metabolic and cardiopulmonary responses of masters recreational runners during running at different speeds

Abstract

This study tested interactions between age and running speed on biomechanics, metabolic responses and cardiopulmonary responses. Three-hundred participants ran at preferred and standardized speeds. Age group (younger, masters [≥40 years]) by speed (self-selected 8.8 km/h, 11.2 km/h and 13.6 km/h) interactions were tested on main outcomes of sagittal kinematic, temporal spatial, metabolic and cardiopulmonary parameters. At all speeds, angular displacements of the ankle, pelvis and knee were less in masters than younger runners (Hedges g effect size range = 0.30-1.04; all p < 0.05). A significant age group by speed interaction existed for hip angular displacement (Wald χ = 10.753; p = 0.013). Masters runners ran at higher relative heart rates (p < 0.05) but at similar rates of oxygen use and energy expenditure. Masters runners used hip-dominant motion and step lengthening as running speed increased, but did not change centre of mass vertical displacement. This may increase mechanical stresses on tissues of the lower extremity in masters runners, especially hamstrings, hip joint and Achilles.

Spatiotemporal and kinematic adjustments in master runners may be associated with the relative physiological effort during running

“…Running with more knee flexion at touch-down and a larger knee joint range of motion has been linked to a higher metabolic demand—i.e., a worse running economy ( 50 – 52 ). Previous studies have found older runners to run with a more flexed knee at touch-down and a smaller knee joint range of motion ( 22 , 25 , 47 ), which would respectively contribute to a worse and better running economy, and thus a negligible net change. In our study, however, master runners only ran with a less flexed knee at touch-down but had a similar knee range of motion to young runners, which together would contribute to a better running economy.…”

“…Age-related changes in running kinematics and performance have indeed been linked previously in short- ( 23 ) and middle-distance ( 24 ) runners. However, trained master runners have also been shown to maintain a similar running economy at sub-maximal speeds compared to young runners, despite having distinct biomechanical characteristics ( 21 , 25 ). Although running economy and performance are influenced by numerous factors, it is yet unclear how this apparent paradox can be explained.…”