AbstractWireless body area network (WBAN) is a novel technology with the incorporation of numerous types of devices, which is also employed in health monitoring applications. Human activity recognition (HAR) receives more interest in recent times along with wearable sensors. HAR system provides information about a person's identity, personality, and psychological state. In the present scenario, it becomes important to model the active learning paradigms with the help of wearable sensors for analysing human activities. Although various deep learning models and existing algorithms secure better outcomes through the sensor data analysis regarding HAR, the decision‐making evaluation seems to be a complex one. The main intent of this paper is to implement the WBAN‐based HAR system using the improved deep learning model. By connecting the wearable sensors, the signals are gathered regarding human activity from diverse benchmark sources. After collecting the required signals, the pre‐processing of the input signals is done using artefact removal and median filtering. Further, the feature extraction is performed, which intends to extract a set of features by utilizing short‐time Fourier transform (STFT) and statistical features. For reducing the feature‐length, a multi‐objective‐based optimal feature selection is adopted. Human activities such as ‘walking, walking upstairs, walking downstairs, sitting, standing, lying, and jogging’ are recognized with help of selected optimal features. The optimized probabilistic neural network (PNN) and convolutional neural network (CNN) are combined and named as adaptive probabilistic‐based CNN (AP‐CNN). The effective performance of optimal feature selection and recognition is accomplished by incorporating the developed backward updating position‐based sea lion optimization algorithm (BU‐SLnO). Finally, the performance of the BU‐SLnO‐AP‐CNN‐based suggested model is analysed, which shows 1.001%, 1.237%, 0.811%, and 0.859% advanced than SLnO‐AP‐CNN, feed‐forward‐AP‐CNN (FF‐AP‐CNN), grey wolf optimization‐AP‐CNN (GWO‐AP‐CNN), particle swarm optimization‐AP‐CNN (PSO‐AP‐CNN) when observing the dataset 1. The experimental outcomes from comparison with various classification techniques demonstrate the efficiency of the developed technique.