Effects Of Periodization Training On Muscular Strength And Power: A Meta-analysis

Periodization is the systematic programming of athletic or physical training that provides critical training parameters to meet athletic performance goals. PURPOSE: This study aims to examine the overall effects of periodization on muscular strength and power, and determine what conditions make the difference in those training outcomes. METHOD: We used four electronic databases including Academic Search Complete, MEDLINE, SPORTDiscus, and Proquest, with the keywords “periodiz*” AND “strength* OR power.” Inclusion criteria: a) used periodization(s) as the training method(s), b) strength and power as primary outcomes, c) reported quantitative measures, and d) published in peer-reviewed and dissertation written in English, from the earliest record to November 2022. Two groups of investigators extracted and crosschecked the data for the analysis. We computed effect sizes (ESs) of Hedges g in a random effects model using the Comprehensive Meta-Analysis version-3 software program. ESs were computed based on a comparison of pre- and post- training data. Subgroup analyses were followed to examine the effect of moderators (periodization type, subject characteristics, body part, length). RESULTS: Our searches identified 44 ESs from 24 studies for strength, and 25 ESs from 21 studies for power. The overall mean ESs are statistically significant for strength (ES = .646, 95% CI = .495-.796, p < .001) and for power (ES = .364, 95% CI = .202-.526, p < .001). Subgroup analyses showed that periodization type (linear, nonlinear, and block), Qbetween (Qb) = 7.550, df = 2, p = .023), and body part (lower and upper), Qbetween (Qb) = 6.028, df = 1, p = .014, partly explained the heterogeneity for strength while only training length (<12 weeks and ≥ 12 weeks), Qbetween (Qb) = 5.296, df = 1, p = .021) moderates power. The subgroup with nonlinear method (ES = .820, 95% CI = .603-1.048) and lower body (ES = .923, 95% CI = .676-1.170) had the highest ES in strength, and ≥ 12 weeks (ES = .581, 95% CI = .338-.823) in power. CONCLUSION: The results showed that periodization training moderately increased strength and power. Also, the nonlinear method appeared to be the most effective in strength, and periodization was more effective in lower body strength. For power, training length over 12 weeks should be considered to obtain the greater benefits.