Effect of linear and weekly undulating resistance training on muscle mass and running performance of project athlete

Introduction: Resistance training is a specialized conditioning method that uses progressively increasing loads and varied training modalities to improve health, fitness, and athletic performance. Periodized RT adjusts training volume and intensity to enhance performance, yet the most effective model remains uncertain. Limited evidence compares linear and weekly undulating periodization, particularly in athletes. Objective: To compare the effects of 12 weeks of linear and weekly undulating resistance training on muscle mass and running performance, as measured by 800 m and 1500 m time trials, in male project athletes. Methodology: A quasi-experimental study design was employed to conduct the study. Thirty-six male runners were randomly assigned to a linear group (n=18) and an undulating group (n=18). Statistical analyses were performed using SPSS V. 26 with a significance level set at P <.05. Paired and independent samples t-tests were analyzed within- and between-group differences. Levene’s test assessed variance homogeneity, Shapiro-Wilk tested normality, and partial eta squared (η²) indicated effect size. Results and Discussion: The results showed no significant differences between the linear resistance training and weekly undulating resistance training groups in muscle mass (t (34) = –.36, p = 0.73, η² = .01), 800 m time trial performance (t (34) = .87, p = .39, η² = .02), or 1500 m time trial performance (t (34) = 1.50, p = .14, η² = .06). Conclusion: Both linear and weekly undulating resistance training produced improvements in muscle mass and middle-distance running performance; however the differences between groups were not statistically significant.