An IoT-enabled CRNN framework for secure wearable sensor-based activity recognition in physical education

Recent advancements in digital technologies have profoundly transformed healthcare delivery, sports analytics, and physical activity surveillance. The accelerated proliferation of wearable sensing devices and Internet of Things (IoT) infrastructures has facilitated unprecedented large-scale acquisition of multimodal physiological and kinematic data. However, accurate recognition of complex human activities remains a formidable challenge, primarily due to inadequate modeling of the spatiotemporal dependencies inherent in wearable-sensor signals. To address these fundamental limitations, this paper proposed a novel IoT-oriented activity recognition framework predicated on a Convolutional Recurrent Neural Network (CRNN) architecture, engineered to simultaneously model the spatial and temporal characteristics of multimodal wearable-sensor data streams. The proposed framework synergistically integrates Convolutional Neural Networks (CNNs) for hierarchical spatial feature extraction with Recurrent Neural Networks (RNNs) for temporal sequence modeling, thereby enabling more discriminative and robust activity classification. The methodological pipeline comprises several sequential stages: First, multidimensional wearable-sensor datasets are employed, encompassing physiological and inertial measurements including heart rate variability, triaxial accelerometer readings, gyroscopic angular velocity, magnetometer orientation data, and cutaneous temperature signals acquired from multiple anatomical locations. Second, raw sensor signals undergo preprocessing and temporal segmentation procedures to enhance data quality and optimize temporal representation. Third, spatiotemporal feature representations are learned autonomously within the hierarchical CRNN architecture. Finally, the proposed model is systematically evaluated through a comparative analysis with five representative baseline methods, encompassing both conventional machine learning algorithms and contemporary deep learning approaches. Experimental results demonstrate that the proposed CRNN framework achieves superior performance, achieving 98.2% classification accuracy, 97.2% sensitivity, 99.2% specificity, 97.4% recall, and 97.6% precision on the evaluated wearable-sensor datasets. Compared with existing methodologies, the proposed model consistently achieves higher recognition accuracy and greater generalization robustness, underscoring its efficacy for wearable-sensor-based activity recognition and its considerable potential for broader deployment in IoT-enabled monitoring paradigms and adaptable solutions in educational settings.