REPLY TO LETTER TO EDITOR: THE DOSE-RESPONSE PHENOMENON ASSOCIATED WITH STRENGTH TRAINING IS INDEPENDENT OF THE VOLUME OF SETS AND REPETITIONS PER SESSION

Alexandre L. Evangelista Tiago V. Braz Roberta L. Rica Welmo A. Barbosa Angelica C. Alonso Jonatas B. Azevedo Bruna M. Barros Marcos R. R. Paunksnis Julien S. Baker Danilo S. Bocalini Julia M. D. Greve About the authors

The recruitment of volunteers took place from the invitation sent to students regularly enrolled in the eighth semester of the Physical Education course. As indicated in the manuscript, the randomization process took place in a block of six subjects, with each block resulting in the distribution of two subjects per group ensuring balanced recruitment in the study favoring the similarity of the measurements at the pre-moment between the groups (3x10 vs. 10x3 vs. 5x6). It is worth mentioning that, according to Yudkin et al. 11. Yudkin PL, Stratton IM. How to deal with regression to the mean in intervention studies. Lancet 1996;347:241–43. and Barnet et al. 22. Barnett AG, van der Pols JC, Dobson AJ. Regression to the mean: what it is and how to deal with it. Int J Epidemiol. 2005;34(1):215-20. , this strategy reduces the risk of bias and is considered as a quality criterion in experimental designs that aims at comparisons between groups.

Additionally, this is a recurring phenomenon in studies with intentional sample selection between groups with strength training 33. Simão R, Spineti J, de Salles BF, Oliveira LF, Matta T, Miranda F, et al. Influence of exercise order on maximum strength and muscle thickness in untrained men. J Sports Sci Med. 2010;1;9(1):1-7.-44. Brigatto FA, Lima LEM, Germano MD, Aoki MS, Braz TV, Lopes CR. High Resistance-Training Volume Enhances Muscle Thickness in Resistance-Trained Men. J Strength Cond Res. 2019. [epub ahead of print] . As an example, we used mode A ultrasound, in accordance with the methodology of previous studies 55. Brigatto FA, Braz TV, Zanini TCDC, Germano MD, Aoki MS, Schoenfeld BJ, et al. Effect of Resistance Training Frequency on Neuromuscular Performance and Muscle Morphology After 8 Weeks in Trained Men. J Strength Cond Res. 2019;33(8):2104-2116.-66. Zaroni RS, Brigatto FA, Schoenfeld BJ, Braz TV, Benvenutti JC, Germano MD, et al. High Resistance-Training Frequency Enhances Muscle Thickness in Resistance-Trained Men. J Strength Cond Res. 2019;33 Suppl 1:S140-S151. , presenting similar absolute values in the muscles analyzed among the subjects in the pre-intervention moment.

With regards to items b and c, we agree and thank the authors of this letter. This failure allowed coherent interpretations mentioned by the authors, which occurred due to an error in the indication of the exercise used to measure the strength of the lower limbs in the present study. Thus, the correct exercise used for the evaluation was the leg press instead of the squat. We indicate that this inconsistency was previously identified by the authors and signaled via email to the Brazilian Journal of Sports Medicine, even before we received the indication of this document. Therefore, it is worth mentioning that the absolute values of the present study, now considered as leg press, are similar to those reported by Lasevicius et al. 77. Lasevicius T, Ugrinowitsch C, Schoenfeld BJ, Roschel H, Tavares LD, De Souza EO, et al. Effects of different intensities of resistance training with equated volume load on muscle strength and hypertrophy. Eur J Sport Sci. 2018;18(6):772-780. , using a similar sample. In addition, we recommend that authors use the term “magic pill” with caution to express positions for future studies.

In fact, the way of quantifying the total load shown in figure 2 was not shown in the manuscript. This equation is classic in literature and has been used in previous studies 88. Scott BR, Duthie GM, Thornton HR, Dascombe BJ. Training Monitoring for Resistance Exercise: Theory and Applications. Sports Med. 2016; 46(5):687-698.-99. Lasevicius T, Schoenfeld BJ, Grgic J, Laurentino G, Tavares LD, Tricoli V. Similar Muscular Adaptations in Resistance Training Performed Two Versus Three Days Per Week. J Hum Kinet. 2019;68:135-143. . Thus, to facilitate clarifications for future readers, we will request the Brazilian Journal of Sports Medicine that this information can be inserted in the chapter of the study design, following the appropriate process. Thank you for your indication.

We understand that the aforementioned studies 1010. Willardson JM, Burkett LN. A comparison of 3 different rest intervals on the exercise volume completed during a workout. J Strength Cond Res. 2005;19(1):23-26.-1111. Willardson JM, Burkett LN. The effect of rest interval length on bench press performance with heavy vs. light loads. J Strength Cond Res. 2006;20(2): 396-399. demonstrate a reduction in the number of repetitions performed with concentric failure when manipulating the pause time between sets. In the present study, the number of repetitions throughout the series in the 3 groups were maintained in the stipulated RM zone (3 vs. 6 vs. 10 repetitions). To maintain this number of repetitions, the weight used for the exercises was adjusted when necessary, in accordance with previous publication 1212. Schoenfeld BJ, Ratamess NA, Peterson MD, Contreras B, Tiryaki-Sonmez G. Influence of Resistance Training Frequency on Muscular Adaptations in Well-Trained Men. J Strength Cond Res. 2015;29(7):1821-9. . Therefore, there was no such reduction in repetition as possibly argued because the external load was adjusted.

It is also necessary to remember that the recovery interval of our methodology should not be considered as “short” but as “moderate”, according to Schoenfeld 1313. Schoenfeld BJ. The mechanisms of muscle hypertrophy and their application to resistance training. J Strength Cond Res. 2010;24(10):2857-72. . According to the author, moderate pauses (between 60 to 90 seconds) offer satisfactory rest time to maximize muscle hypertrophy. Furthermore, a classic study still indicates that strength is restored within the first minute of recovery 1414. Stull GA, Clarke DH. Patterns of recovery following isometric and isotonic strength decrement. Med Sci Sports 1971; 3: 135–139. .

Finally, one of the articles 1111. Willardson JM, Burkett LN. The effect of rest interval length on bench press performance with heavy vs. light loads. J Strength Cond Res. 2006;20(2): 396-399. cited by the authors of this letter used a methodology quite different from the present study. Which makes possible comparisons and / or inferences about the influence of recovery difficult to establish.

REFERENCES

  • 1
    Yudkin PL, Stratton IM. How to deal with regression to the mean in intervention studies. Lancet 1996;347:241–43.
  • 2
    Barnett AG, van der Pols JC, Dobson AJ. Regression to the mean: what it is and how to deal with it. Int J Epidemiol. 2005;34(1):215-20.
  • 3
    Simão R, Spineti J, de Salles BF, Oliveira LF, Matta T, Miranda F, et al. Influence of exercise order on maximum strength and muscle thickness in untrained men. J Sports Sci Med. 2010;1;9(1):1-7.
  • 4
    Brigatto FA, Lima LEM, Germano MD, Aoki MS, Braz TV, Lopes CR. High Resistance-Training Volume Enhances Muscle Thickness in Resistance-Trained Men. J Strength Cond Res. 2019. [epub ahead of print]
  • 5
    Brigatto FA, Braz TV, Zanini TCDC, Germano MD, Aoki MS, Schoenfeld BJ, et al. Effect of Resistance Training Frequency on Neuromuscular Performance and Muscle Morphology After 8 Weeks in Trained Men. J Strength Cond Res. 2019;33(8):2104-2116.
  • 6
    Zaroni RS, Brigatto FA, Schoenfeld BJ, Braz TV, Benvenutti JC, Germano MD, et al. High Resistance-Training Frequency Enhances Muscle Thickness in Resistance-Trained Men. J Strength Cond Res. 2019;33 Suppl 1:S140-S151.
  • 7
    Lasevicius T, Ugrinowitsch C, Schoenfeld BJ, Roschel H, Tavares LD, De Souza EO, et al. Effects of different intensities of resistance training with equated volume load on muscle strength and hypertrophy. Eur J Sport Sci. 2018;18(6):772-780.
  • 8
    Scott BR, Duthie GM, Thornton HR, Dascombe BJ. Training Monitoring for Resistance Exercise: Theory and Applications. Sports Med. 2016; 46(5):687-698.
  • 9
    Lasevicius T, Schoenfeld BJ, Grgic J, Laurentino G, Tavares LD, Tricoli V. Similar Muscular Adaptations in Resistance Training Performed Two Versus Three Days Per Week. J Hum Kinet. 2019;68:135-143.
  • 10
    Willardson JM, Burkett LN. A comparison of 3 different rest intervals on the exercise volume completed during a workout. J Strength Cond Res. 2005;19(1):23-26.
  • 11
    Willardson JM, Burkett LN. The effect of rest interval length on bench press performance with heavy vs. light loads. J Strength Cond Res. 2006;20(2): 396-399.
  • 12
    Schoenfeld BJ, Ratamess NA, Peterson MD, Contreras B, Tiryaki-Sonmez G. Influence of Resistance Training Frequency on Muscular Adaptations in Well-Trained Men. J Strength Cond Res. 2015;29(7):1821-9.
  • 13
    Schoenfeld BJ. The mechanisms of muscle hypertrophy and their application to resistance training. J Strength Cond Res. 2010;24(10):2857-72.
  • 14
    Stull GA, Clarke DH. Patterns of recovery following isometric and isotonic strength decrement. Med Sci Sports 1971; 3: 135–139.

Publication Dates

  • Publication in this collection
    14 June 2021
  • Date of issue
    Apr/Jun 2021
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