Maintaining proper form while exercising is important for preventing injuries and maximizing muscle mass gains. While fitness apps are becoming popular, they lack the functionality to detect errors in workout form. Detecting such errors naturally requires estimating users' body pose. However, off-the-shelf pose estimators struggle to perform well on the videos recorded in gym scenarios due to factors such as camera angles, occlusion from gym equipment, illumination, and clothing. To aggravate the problem, the errors to be detected in the workouts are very subtle. To that end, we propose to learn exercise-specific representations from unlabeled samples such that a small dataset annotated by experts suffices for supervised error detection. In particular, our domain knowledge-informed self-supervised approaches exploit the harmonic motion of the exercise actions, and capitalize on the large variances in camera angles, clothes, and illumination to learn powerful representations. To facilitate our self-supervised pretraining, and supervised finetuning, we curated a new exercise dataset, Fitness-AQA, comprising of three exercises: BackSquat, BarbellRow, and OverheadPress. It has been annotated by expert trainers for multiple crucial and typically occurring exercise errors. Experimental results show that our self-supervised representations outperform off-the-shelf 2D- and 3D-pose estimators and several other baselines.

通过自监督的学习和对锻炼形式的理解，我们提出了一种在容易出现镜头角度、遮挡和光照变化的体育馆场景下，能够有效对运动员姿势进行检测的方法。我们还针对此目的创建了一个包含三种训练动作的新锻炼数据集，并且其自监督特征的表现超过了现有的2D和3D姿态估计器。

基于领域知识的自监督表示学习用于Workout Form评估