Physics of Weightlifting*

In the footsteps of J.B. Keller who determined the optimal strategy to run a race [1], we investigate weightlifting records. We measure the dynamics of lifting barbells of different masses at Bench Press for different athletes. To understand the shape of experimental results, we need both a macroscopic mechanic model and microscopic description of muscle contraction. We dive into muscle in order to understand the relation between force generated by the muscle and its contraction velocity [2,3] and draw a capillary analogy of muscle contraction. Finally we use the Deshcherevskii kinetik model [4] and derive the dynamics of the barbell. From the fit between data and predictions, we extract microscopic characteristics of muscles. We consider to apply this protocole to diagnose muscle aging or dysfunctions. \\[4pt] [1] Keller, J. B. (1973). iA theory of competitive running. Physics today, 43.\\[0pt] [2] Hill, A. V. (1938). The heat of shortening and the dynamic constants of muscle. Proceedings of the Royal Society of London. Series B, Biological Sciences, 136-195.\\[0pt] [3] Huxley, H. E. (1990). Sliding filaments and molecular motile systems. J. Biol. Chem, 265(15), 8347-8350.\\[0pt] [4] Deshcherevskii, V. I. (1971). A kinetic theory of striated muscle contraction. Biorheology, 7(3), 147-170.