Background: The lunge exercise is commonly adopted in public fitness programs. However, inadequate training experience and knowledge may result in improper actions, resulting in lowering training efficacy and possibly causing exercise-related diseases. Methods: Twenty-four male fitness trainees (12 novices and 12 experienced seniors) were recruited. Kinematics, kinetics, and muscle activation were measured during forward and backward lunges with different loading positions. Two-way repeated measures ANOVA and one-dimensional statistical parametric mapping (SPM1D) were employed to explore various between training experience across different loading positions and lunge directions. Results: Hip, knee, and ankle ROM and angle peaks were significantly greater in novices than in seniors (P < 0.001). During forward lunges, dumbbells reduced hip moments and stiffness in novices (P < 0.001), while barbells increased ankle moments in seniors (P = 0.022). In the backward lunges, novices showed increased negative power and significant joint instability with dumbbells. Conclusions: Training experience is the significant influence during male lunge exercises. Novices show more stability when using dumbbells instead of barbells for forward lunges. Novices are less stable during backward lunges than more experienced seniors. Overall, novices get a greater benefit of training with dumbbells, while seniors are less likely to hurt their knees and ankles when they use barbells.