Effects of daily undulating (DUP) and linear periodization (LP) models to increase lower body strength and power in premenopausal women

Resumen

Introduction The effects of linear (LP) and daily undulating periodized (DUP) resistance training (RT) periodization strategies were examined on a group of premenopausal women. Method Eighty-nine, fitness trained premenopausal women with no experience in resistance training with free weight or machine, aged ±SD) 32,62 ± 5.98, were randomly assigned to an LP (n = 33), DUP (n = 29) or control (CON) group (n=27). Before and after a 12 week period intervention, the subjects performed a progressive load test (PLT) aimed to determine the 1 RM, Peak Power [Ppwt], Average Power [Apwt], Relative Load [RelOL], Optimal Load[OL], Relative Power [Aprel] in a parallel squat machine (PSM). Body composition variables (Body Fat Percentage [BF%], Body Mass Index [BMI], Body Weight [BW], Waist to Hip Ratio [WHR], thigh and calf circumference) were tested with an InBody720 Body Composition Analyzer at a baseline and at the end of the study. The training protocols for LP and DUP were developed with a frequency of 3 d/wk with 3 mesocycles. The DUP group underwent a hypertrophy type training (3 sets of 10 RM, 70-80% of 1 RM), strength training (3 sets of 6 RM, 80-90% of 1 RM) and power training (3 sets of 8 RM, 30-40% of 1 RM). LP group performed in the first mesocycle, 3 sets of 10 RM (65-70% of 1 RM); in the second mesocycle, 3 sets of 8 RM (75-80% of 1 RM); in the third mesocycle, 3 sets of 6 RM (85-90% of 1 RM). Both the RT programs were equalized. Oneway ANOVA, and LSD post hoc statistical tests were used to calculate significant differences (p<0.05) between groups. A paired-samples t test was calculated to compare the mean pretest (T1) scores to the mean post test (T2) scores. Effect sizes (ES) were calculated to examine the magnitude of treatment effect elicited by DUP and LP models for strength and/or power development. In order to reveal the affects of baseline differences, analysis of covariance (ANCOVA) univariate general linear model was conducted for this study. Results At T2 significant increases (p <0.05), of 19,86% and 16,22% in 1RM and 17,98% and 15, 35% in Relative Strength (RS) were observed for DUP and LP groups, respectively. Both DUP and LP had large effects on maximal strength development (ES= 1,19; ES=1,21), respectively. For Ppwt, both groups significantly (p <0.05) increased, (DUP of 17,24 %, LP of 14,95 %). DUP model had large effect on Ppwt improvement (0,85), while LP had moderate effect (0,61). In Aprel, the LP and DUP groups exhibited a significant increase (p ¿0.05), of 15,19% and 11,57% at T2 compared with T1, respectively. Additionally, in Apwt both DUP and LP groups showed significant increase (p ¿0.05), of 12.19% and 15,62%, respectively, compared to the CON group. On Apwt development, DUP was largely (ES= 0,85), LP moderately effective (ES=0,61) whereas on Aprel LP had large effect, DUP had moderate effect. The DUP group significantly increased (p ¿0.05) in OL variable of 14,13%, compared to the CON group. A significant increase (p¿0.05) from pretest (T1) to post test (T2) was found in DUP (14,13%) in OL values, which also showed a moderate treatment effect (0,68). No significant changes (p ¿0.05), were evaluated in RelOL between the tests and groups. The DUP group increased most in 1RM strength and Ppwt, and LP group increased most in Aprel, but no statistical differences (p ¿0.05) were found between the groups in any measured strength/power variables. In body composition variables changed signi cantly in DUP by 1,66 % ( 1,07 kg) compared to LP group of 0,23% ( 0,15 kg). There was a significant increase (p¿0.05) in BW in DUP (1,66%) from pretest (T1) to post test (T2). LSD post hoc test revealed significant (p ¿0.05) MI changes in DUP of 1,73%, compared to CON of 0,66% and LP of 0,23 % groups at the end of the study. A significant increase (p¿0.05) from pretest (T1) to post test (T2) was found in DUP (1,73 %) in BMI values. Despite of the significant changes in BW and BMI, the analysis of ES showed very small differences. No statistical differences (p ¿0.05) were found between groups and tests in thigh, calf, F% and HR variables. Conclusion Daily intensity and volume variations were as effective as linear variations. Both undulating and linear periodization had large effects on maximal strength and power development, and no significant (p>0.05) statistical differences were found between groups. The DUP and LP resistance training periodization models used in the study proved equally adept in improving different strength and power qualities and promoted musculoskeletal strength and power of fitness trained premenopausal women with no experience in resistance training with free weight or machine. In order to observe further changes in the subjects¿ body composition parameters, longer training periods are required. Further studies are needed to compare LP and DUP models with extended training duration, as well as research with untrained pre- and postmenopausal women populations.