We present a novel system for camera-based measurement and visualization of muscle work based on the Hill-Type-Muscle-Model: the exercise exertion muscle-work monitor (\textit{XEM}$^{2}$). Our aim is to complement and, thus, address issues of established measurement techniques that offer imprecise data for non-uniform movements (burned calories) or provide limited information on strain across different body parts (self-perception scales). We validate the reliability of XEM's measurements through a technical evaluation of ten participants and five exercises. Further, we assess the acceptance, usefulness, benefits, and opportunities of \textit{XEM}$^{2}$ in an empirical user study. Our results show that \textit{XEM}$^{2}$ provides reliable values of muscle work and supports participants in understanding their workout while also providing reliable information about perceived exertion per muscle group. With this paper, we introduce a novel system capable of measuring and visualizing exertion for single muscle groups, which has the potential to improve exercise monitoring to prevent unbalanced workouts.

翻译：本文提出了一种基于希尔型肌肉模型的摄像头式肌肉功测量与可视化系统：运动负荷肌肉功监测器（\textit{XEM}$^{2}$）。该系统旨在补充现有测量技术的不足，这些技术或对非均匀运动提供不精确数据（如消耗卡路里），或对不同身体部位的负荷信息提供有限（如自感劳累分级表）。我们通过对十名参与者进行五项训练的技术评估，验证了XEM测量的可靠性。此外，我们通过实证用户研究评估了\textit{XEM}$^{2}$的接受度、实用性、优势及应用前景。研究结果表明，\textit{XEM}$^{2}$能提供可靠的肌肉功数值，帮助参与者理解其训练状态，同时为各肌群的主观劳累感提供可靠信息。本文提出的新型系统能够测量并可视化单一肌群的训练负荷，有望改进运动监测方式，从而预防训练不均衡的问题。