title: Stride angle as a novel indicator of running economy in well-trained runners.
abstract: The main purpose of this study was to investigate the relationship between a novel biomechanical variable, the stride angle, and running economy (RE) in a homogeneous group of long-distance athletes. Twenty-five well-trained male runners completed 4-minute running stages on a treadmill at different set velocities. During the test, biomechanical variables such as stride angle, swing time, ground contact time, stride length, stride frequency, and the different sub-phases of ground contact were recorded using an optical measurement system. VO2 values at velocities below the lactate threshold were measured to calculate RE. Stride angle was negatively correlated with RE at every speed (p < 0.001, large effect sizes). Running economy was also negatively correlated with swing phase and positively correlated with ground contact time and running performance according to the best 10-km race time (p ≤ 0.05, moderate and large effect sizes). Last, stride angle was correlated with ground contact time at every speed (p < 0.001, large effect sizes). In conclusion, it seems that optimal execution of stride angle allows runners to minimize contact time during ground contact, whereby facilitating a better RE. Coaches and/or athletes may find stride angle a useful and easily obtainable measure to track and make alterations to running technique, because changes in stride angle may influence the energy cost of running and lead to improved performance.
authors.affiliation: 1UCT/MRC Research Unit for Exercise and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa; 2Department of Physical Education and Sport, University of the Basque Country UPV/EHU, Vitoria-Gasteiz, Spain; and 3Department of Physiology, University of the Basque Country UPV/EHU, Leioa, Spain.
authors.forename: Jordan
authors.initials: J
authors.lastname: Santos-Concejero
authors.forename: Nicholas
authors.initials: N
authors.lastname: Tam
authors.forename: Cristina
authors.initials: C
authors.lastname: Granados
authors.forename: Jon
authors.initials: J
authors.lastname: Irazusta
authors.forename: Iraia
authors.initials: I
authors.lastname: Bidaurrazaga-Letona
authors.forename: Jon
authors.initials: J
authors.lastname: Zabala-Lili
authors.forename: Susana M
authors.initials: SM
authors.lastname: Gil
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology; D001696:Biomechanical Phenomena; D005080:Exercise Test; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D012420:Running / Q000502:physiology*; D055815:Young Adult
chemical_list: D019344:Lactic Acid