Predicting anaerobic power status of taekwondo athletes from anthropometric and biomechanical features: a multi-branch attention deep network with SHAP and LIME interpretability
摘要
Anaerobic power is a core physical fitness indicator that substantially influences competitive performance in taekwondo; however, the Wingate 30-second test (WAnT) imposes stringent laboratory requirements and demands specialised equipment, making it impractical for widespread deployment in grassroots training settings. This study aims to investigate the feasibility of predicting the anaerobic power level (high vs. low) of taekwondo athletes from inexpensive and readily accessible anthropometric and biomechanical features, and to propose a domain-aware deep learning model tailored to the small-sample sports science scenario. Using a publicly available dataset comprising 320 elite taekwondo athletes (177 male, 143 female), 19 anthropometric and biomechanical features were collected, and binary classification labels (high/low power, 161 vs. 159) were constructed by thresholding the relative Wingate peak power (W/kg) at the gender-stratified median (female median 8.41 W/kg, male median 11.97 W/kg). We propose the anthropometric–biomechanical multi-branch attention network (ABM-Net), which explicitly models the domain knowledge structure of anthropometric–biomechanical features through intra-branch self-attention encoding across three parallel branches and bidirectional cross-branch attention mechanisms, augmented by a learnable linear residual bypass and several small-sample regularisation strategies (label-smoothed BCE, Mixup, SWA, and a 5-seed deep ensemble). Under a unified 5-fold stratified cross-validation scheme (random_state = 2024), ABM-Net was systematically compared with 11 models comprising 5 classical machine learning baselines and 5 tabular deep learning baselines, with six evaluation metrics reported: accuracy, precision, recall, F1-score, AUC-ROC, and Matthews Correlation Coefficient (MCC). SHAP and LIME were additionally applied to conduct a dual-method interpretability analysis of ABM-Net. ABM-Net obtained the best accuracy (0.8562), precision (0.8485), and MCC (0.7127) among the 11 models; however, a logistic-regression baseline reached a marginally higher F1 (0.8597 vs. 0.8589) and AUC (0.9379 vs. 0.9317), so ABM-Net’s advantage is confined to MCC and specificity (0.843) and should be read as a modest rather than across-the-board improvement. Permutation importance ranked gender (