Int J Sports Med
DOI: 10.1055/a-1432-2336
Training & Testing

Continuous Analysis of Marathon Running Using Inertial Sensors: Hitting Two Walls?

1  Institute of Sport Sciences, University of Lausanne Lausanne, Switzerland
2  Department of informatikk, University of Oslo, Faculty of Mathematics and Natural Sciences, Oslo, Norway
,
Mathieu Falbriard
3  Laboratory of Movement Analysis and Measurement (LMAM), EPFL, Lausanne, Switzerland
,
Benoit Mariani
4  Department of SA, Gait Up, Lausanne, Switzerland
,
Kamiar Aminian
3  Laboratory of Movement Analysis and Measurement (LMAM), EPFL, Lausanne, Switzerland
,
Gregoire P. Millet
1  Institute of Sport Sciences, University of Lausanne Lausanne, Switzerland
› Author Affiliations

Abstract

Marathon running involves complex mechanisms that cannot be measured with objective metrics or laboratory equipment. The emergence of wearable sensors introduced new opportunities, allowing the continuous recording of relevant parameters. The present study aimed to assess the evolution of stride-by-stride spatio-temporal parameters, stiffness, and foot strike angle during a marathon and determine possible abrupt changes in running patterns. Twelve recreational runners were equipped with a Global Navigation Satellite System watch, and two inertial measurement units clamped on each foot during a marathon race. Data were split into eight 5-km sections and only level parts were analyzed. We observed gradual increases in contact time and duty factor as well as decreases in flight time, swing time, stride length, speed, maximal vertical force and stiffness during the race. Surprisingly, the average foot strike angle decreased during the race, but each participant maintained a rearfoot strike until the end. Two abrupt changes were also detected around km 25 and km 35. These two breaks are possibly due to the alteration of the stretch-shortening cycle combined with physiological limits. This study highlights new measurable phenomena that can only be analyzed through continuous monitoring of runners over a long period of time.



Publication History

Received: 27 February 2021

Accepted: 03 March 2021

Publication Date:
11 May 2021 (online)

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