Effect of linear and nonlinear periodized programs on muscular strength and endurance in untrained adolescence girls

The effect of periodization has been confirmed on the training adaptations; but the most effective approach are not known well for strength and endurance development for a wide variety of populations; therefore, the aim of present study was to investigate the effect of linear periodized (LP) and Nonlinear periodized (NLP) resistance training on muscular strength and endurance in untrained adolescence girls.

A number of 23 untrained adolescence girls were randomly assigned into 3 groups including control group, LP group, and NLP group. The linear model of periodization include a volume decrease and an intensity gradually increase as training progressive and the nonlinear model of periodization includes an increase and decrease of the intensity and volume training, respectively during cycles training. 48 hours before and after 8 weeks protocols, the upper and lower body muscular strength were assessed via 1RM leg press and bench press movements respectively, and lower and upper body muscular endurance were measured through push up and squat movement, respectively as well. The data was analyzed using ANCOVA test and the significance level was considered if p<0.05.

Data analysis showed that LP and NLP significantly increased upper and lower body muscular strength, upper body muscular endurance (p<0.001), lower body muscular endurance (p=0.01 ), and decrease body fat percent (p=0.04). In addition, LP led to more increase in lower body muscular strength (p=0.04), and NLP led to more increase in upper body muscular endurance (p=0.03), while there was no significant difference in explosive power (p=0.07), upper body muscular strength (p=0.88), lower body muscular endurance (p=0.99) and body fat percent (p=0.64) between LP and NLP groups (p>0.05).

Although muscular strength and endurance are improved by the LP and NLP models; the LP model is better training method to improve lower body muscular strength and NLP model is a more approach to improve upper body muscular endurance in untrained adolescence girls, although strength and endurance of muscles are improved in the result of LP and NLP models.