Graduation Date
Spring 2026
Document Type
Thesis
Program
Master of Science degree with a major in Kinesiology, option Exercise Science
Committee Chair Name
Young Sub Kwon
Committee Chair Affiliation
Cal Poly Humboldt Faculty or Staff
Second Committee Member Name
Dr. Rock Braithewaite
Second Committee Member Affiliation
Cal Poly Humboldt Faculty or Staff
Third Committee Member Name
Andrew Peterson
Keywords
Muscular fitness, Resistance training, Free-weight, Back squat, Hypertrophy
Subject Categories
Kinesiology
Abstract
Muscular fitness is a critical component of health-related fitness and a strong predictor of functional capacity, injury risk, and long-term participation in physical activity. Despite the widespread use of the free-weight back squat in rehabilitation and resistance training, sex-specific normative reference values for squat performance under hypertrophy-oriented loading conditions are limited.
This study aimed to establish sex-specific normative reference values for back-squat one-repetition maximum (1RM) strength and multi-set repetition performance in healthy, college-aged adults (20-29 years). Subjects completed a hypertrophy-oriented protocol consisting of four sets at 75% of 1RM with 90-second rest intervals.
A total of 138 subjects (52 women, 86 men) were included in the final analyses. Men demonstrated greater absolute and relative 1RM strength across all normalization methods (d = 0.81 - 2.03). Women performed more repetitions in Set 4, but this did not meet the significance threshold (p = 0.027; d = 0.43). In contrast, men exhibited a greater decline in repetition performance across sets (percent decline in repetitions; Drop%). Men also demonstrated a more negative repetition slope across sets at 75% 1RM (Slope 75), but did not reach statistical significance (p = 0.054; d = 0.34). Total training volume was greater in men (d = 0.31 - 1.29). Percentile ranks (5th-95th) were generated for all variables by sex and for the combined sample.
These findings provide the first normative reference standards for back squat performance under a hypertrophy-oriented resistance training protocol, offering practical benchmarks for strength and conditioning specialists and exercise professionals.
Key Words: resistance training, back squat, muscular endurance, sex differences, normative data, hypertrophy.
Recommended Citation
Medina, Luis, "Preliminary study on free-weight back squat muscular hypertrophy reference values" (2026). Cal Poly Humboldt theses and projects. 2542.
https://digitalcommons.humboldt.edu/etd/2542