Individual Muscle Hypertrophy and Strength Responses to High vs. Low Resistance Training Frequencies
As health and wellness professionals, you might have found yourself being involved in a debate or discussion whether high frequency or low frequency resistance training would result in the highest amount of muscular gain and strength output. A heavy topic within our professional community lies on the discussion of resistance training weekly frequency and its effect on muscular hypertrophy and strength development (Damas et al., 2019). To explore this discussion, Damas et al. (2019) conducted a study to investigate the muscular and strength adaptations of male subjects with ages ranging from 18 to 30 years. The researchers of the study utilized previous research “showing the time course of increases in muscle protein synthesis after [resistance training] session (lasting ∼24–48 hours after session (Damas, et al., 2019), to confirm their desire to explore the impact that different frequencies of resistance training bouts have on muscle hypertrophy and strength. Damas et al. (2019) stated in their research that previous studies discovered similar improved in muscle hypertrophy and strength in untrained individuals after 8 weeks through performing resistance training 2, 3, or 5 times per week, “even with a higher 8-week accumulated total training volume (TTV) for the higher frequency (sets × reps × load) (Damas et al., 2019).” Before performing the study, researchers received clearance from the Federal University of São Carlos Ethic Committee, received signed informed consent forms from all participants, and aligned the study to stay “in accordance with the ethical standards of the institutional research committee and with the Helsinki declaration (Damas, et al., 2019). The researchers decided to assess the cross-sectional area of the vastus lateralis muscle of the subjects prior and post 8 weeks of the resistance training protocol. Subjects were to perform their training protocol of 3 sets of their 9-rep maximum to 12 rep maximum until muscular failure. All subjects were allowed a 2-minute rest period between each set, due to the researchers’ claim of sufficient rest for generating hypertrophy and strength adaptations (Damas, et al., 2019). Subjects utilized each leg as individual testing units, categorizing one leg in the high frequency (HF) training protocol (legs allocated to the 5× per week resistance training protocol) and the other in the low frequency (LF) training protocol (legs allocated to 2 or 3× per week resistance training protocol). The changes in muscle cross-sectional area, accumulated total training volume, and 1 rep max values were compared between high frequency and low frequency using paired t-tests. Participants were classified as “responders” or “nonresponders” to resistance training based on the evaluated t-tests. The high frequency training units had accumulated more total training volume than the low frequency training units. In regards to muscular hypertrophy, 31.6% of subjects (6 participants) responded more to high frequency resistance training, while 36.8% of subjects (7 participants) responded more to low frequency. The 31.6% of subjects remaining (6 participants), showed no difference in the “hypertrophic responses between training frequencies (Damas, et al., 2019).” In regards to muscular strength 26.3% of subjects (5 participants) increased their 1 rep max value for high frequency, 15.8% of subjects (3 participants) and the other 57.9% of subjects (11 participants) showed similar responses in both high frequency and low frequency resistance training protocols. Cross-sectional area and total training volume had absolutely no significant correlations.
Damas, et al. (2019) research study on muscular and strength adaptations to high frequency and low frequency resistance training explored adaptations to specific training protocols but did not give us some detailed insight to the actual training. With the sets, reps, and intensity specified, it could have been more unique and insightful for the researchers to display the progression in 1 rep max, weight performed during training, and output progression of each individual. The data on training progression would allow viewers to observe and analyze each individual during the study. I’m sure the data was collects, but seemed unimportant to the researcher to display within the actual article. Along with training load, we have a lack of understanding of the actual repetition tempo performed by each individual. Some participants might have controlled the eccentric phase of the exercise while others allowed relaxation and ceased tension of the quadriceps. Tempo and tension are vital in understanding muscular hypertrophy and strength. Another topic of discussion in regards to the research could be the specific exercise selection. I bet the researchers chose the leg extension due to its isolation of the quadricep muscles, but do you think a compound exercise might display different results? If you performed a back or goblet squat, would full body integrity, lower back fatigue, and overall energy output be a factor in resistance training frequency, volume, and intensity? The study was conducted on untrained individuals utilizing a leg extension machine, eliminating so many real-world application factors and variables. As fitness professionals, you must understand how you could and how you shouldn’t apply this in an exercise prescription based on accumulated overall, nerve, and muscular fatigue of the participant. The limitations of the study, and those that could impact a study conducted on free weight training, could include the variability of exercise form and muscular contraction. You would then have to enforce proper form, supervise sessions, and regulate bar path to fully determine progression. With this, torque based on limb length might also be vital to understanding the impact that a specific training load has on the musculature of an individual.
I chose to analyze the literature and display my understanding of the content due to the fact that the discussion on whether low frequency or high frequency resistance training is better for muscle hypertrophy or strength gains is carried out among many facilities that I service. I find it fascinating to be able to display research studies and proven data behind anything I state or present. This article might not be the make or break to understanding training frequency, but it definitely helps fight the battle. I did find this piece very relevant and informative due to the importance that proper training prescription has on my job and career with injury prevention for first responders. The more information I can gather on resistance training and injury prevention, the better I can service first responders all over the nation.
Author of Review: Hussien Jabai
Damas, F., Barcelos, C., Nóbrega, S. Ugrinowitsch, C., Lixandrão, M., Santos, L., Conceição, M., Vechin, F., Libardi, C. (2019). Individual Muscle Hypertrophy and Strength Responses to High vs. Low Resistance Training Frequencies. The Journal of Strenght and Conditioning Research, 33(4), 897-901. Retrieved from https://journals.lww.com/nsca-jscr/Fulltext/2019/04000/Individual_Muscle_Hypertrophy_and_Strength.1.aspx.