Volume-Equated High and Low Repetition Daily Undulating Periodization Models for Upper Body Muscle Hypertrophy

Abstract

Traditionally, 8-12 repetitions have been recommended to maximize muscle hypertrophy. However, recent research suggests total training volume independent of specific repetition ranges is the most important variable for hypertrophy. Despite this, volume-equated daily undulating periodization (DUP) models with various repetition ranges have yet to be investigated for hypertrophy. PURPOSE: To compare changes in muscle hypertrophy in high repetition daily undulating periodization (DUP-HR) and low repetition daily undulating periodization (DUP-LR), models. METHODS: Fifteen males (age: 22.9±3.0 yrs, weight: 83.3±12.0kg., body fat: 11.2±4.5%) with a minimum of 2yrs. resistance training experience, and a frequency of ≥ 1 day/wk. bench press over the past 6 months were assigned to one of two DUP groups: 1) DUP-HR (n=7): 12 repetitions (Mon), 10 repetitions (Wed), and 8 repetitions (Fri) or 2) DUP-LR (n=8): 6 repetitions (Mon), 4 repetitions (Wed), and 2 repetitions (Fri). Subjects performed the bench press exercise each session. The study spanned 8 total weeks. Week 1 served as pre-testing and introductory training, weeks 2-7 serving as the main training program, and week 8 a taper training week and post-testing. Hypertrophy was assessed pre- and post-training by muscle thickness (MT) via ultrasonography (BodyMetrix, IntelaMetrix, Livermore, CA.). MT measurements were taken of the left chest and right chest and then summed for total chest MT. A 2 x 2 repeated measures ANOVA was used with significance set at p≤0.05. RESULTS: Both groups increased (p<0.05) chest MT (DUP-HR-pre: 72.33±8.64mm - post: 78.78± 7.41mm and DUP-LR-pre: 74.63±13.96mm- post: 82.71±17.22mm), however there were no group differences (p>0.05). Percent changes from pre to post-testing were +10.8% and +8.9% in DUP-LR and DUP-HR respectively. CONCLUSION: Our findings demonstrate that DUP is an effective method to increase muscle hypertrophy over a short-term training program in previously trained individuals. Further, this data suggests that muscle hypertrophy is volume-dependent and not determined by a specific repetition range.