The results of constructing a nonlinear model of sarcomere contraction have been summarized. A strange attractor has been obtained, which is related to the randomness of the dynamics of the order parameter during the sarcomere deformation. The hypothesis has been proposed that when actin filaments in the sarcomere are fixed, the myosin system undergoes nonlinear oscillations with dissipation, which leads to temperature increase. The increase in temperature has been determined for pulsations of the inertial range. Normalized spectra of the power of pulsations of the order parameter have been constructed for the model by the Fourier-transform method. The thermodynamics of the contraction of the sarcomere has been considered.