Licentiate seminar in mechanical engineering with Julius Lidar

Supervisors

Prof. Mikael Bäckström, main supervisor

Doc. Mats Ainegren

Dr. David Sundström

External reviewer

Prof. Dr. Dietmar Saupe, Universität Konstanz

Abstract

Endurance athletes strive to improve their race times by enhancing their physical abilities, techniques, tactics, and equipment. Numerical simulations can aid in this effort by enabling repeated testing under identical conditions, thus isolating the effect of a single variable of interest on race time. This thesis outlines the mechanical assumptions and mathematical formulations to conducting numerical simulations. Paper I exemplifies applications and limitations when using numerical simulations with a propulsive power model, by investigating the impact of dynamic friction on race times in cross-country skiing.

Further, the thesis introduces bioenergetic modeling as a possible method for more accurately modeling an athlete’s propulsive power. It provides an overview of existing bioenergetic models and describes a non-linear grey-box parameter estimation method for individualizing bioenergetic model formulations to reflect an individual athlete’s bioenergetic systems. In Paper II, an assessment of validation for two existing bioenergetic models is performed on an individual level when applied to simulated sprint time trials in cross-country skiing. The models show overall good agreement with measurement data but lack the ability to capture the dynamics of the human metabolic energy systems in more detail.

In Paper III, a new bioenergetic model is developed which describes the dynamic behavior of the metabolic energy supply systems and various sources of metabolic demand. The model is individualized and validated against intermittent cycling with varying power output. Although the model shows good agreement with measurements, it does not capture the details of the aerobic slow component and periods of recovery, indicating a need for continued development.

Download from Diva