Efficacy of a new strength training design: the 3/7 method
This study investigated the efficacy of a new strength training method on strength gain, hypertrophy, and neuromuscular fatigability.
The training exercise consisted of elbow flexion against a load of ~ 70% of one repetition maximal (1RM). A new method (3/7 method) consisting of five sets of an increasing number of repetitions (3 to 7) during successive sets and brief inter-set intervals (15 s) was repeated two times after 150 s of recovery and compared to a method consisting of eight sets of six repetitions with an inter-set interval of 150 s (8 × 6 method). Subjects trained two times per week during 12 weeks. Strength gain [1RM load and maximal isometric voluntary contraction (MVC)], EMG activity of biceps brachii and brachioradialis, as well as biceps’ brachii thickness were measured. Change in neuromuscular fatigability was assessed as the maximal number of repetitions performed at 70% of 1RM before and after training.
Both 3/7 and 8 × 6 methods increased 1RM load (22.2 ± 7.4 and 12.1 ± 6.6%, respectively; p < 0.05) and MVC force (15.7 ± 8.2 and 9.5 ± 9.5%; p < 0.05) with a greater 1RM gain (p < 0.05) for the 3/7 method. Normalized (%Mmax) EMG activity of elbow flexors increased (p < 0.05) similarly (14.5 ± 23.2 vs. 8.1 ± 20.5%; p > 0.05) after both methods but biceps’ brachii thickness increased to a greater extent (9.6 ± 3.6 vs. 5.5 ± 3.7%; p < 0.05) for the 3/7 method. Despite subjects performing more repetitions with the same absolute load after training, neuromuscular fatigability increased (p < 0.05) after the two training methods.
The 3/7 method provides a better stimulus for strength gain and muscle hypertrophy than the 8 × 6 method.
KeywordsMuscle strength Hypertrophy Fatigability Electromyography Ultrasonography Near-infrared spectroscopy
One repetition maximal
Averaged value of the rectified EMG
Analysis of variance
Coefficient of variation
Intraclass correlation coefficient
Maximal motor wave
Maximal voluntary contraction
Tissue oxygenation index
The authors thank Angélique Manier, Maxime Tomi and Joachim Ribanje for their assistance in supervising training sessions and in collecting data.
JD, SB, AC conceived the study. SS collected and analysed the data and prepared the figures. All authors interpreted the results, contributed to the writing of the paper and edited the final draft of the manuscript.
This study was supported by a grant of the Sports Ministry of the Wallonia-Brussels Federation of Belgium.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Brown JM, Solomon C, Paton M (1993) Further evidence of functional differentiation within biceps brachii. Electromyogr Clin Neurophysiol 33:301–309Google Scholar
- Damas F, Phillips SM, Libardi CA, Vechin FC, Lixandrão ME, Jannig PR, Costa LA, Bacurau AV, Snijders T, Parise G, Tricoli V, Roschel H, Ugrinowitsch C (2016) Resistance training-induced changes in integrated myofibrillar protein synthesis are related to hypertrophy only after attenuation of muscle damage. J Physiol 594:5209–5222CrossRefGoogle Scholar
- Duchateau J, Baudry S (2011) Training adaptation of the neuromuscular system. In: Komi PV (ed) Neuromuscular aspects of sport performance. Wiley-Blackwell, Oxford, pp 216–253Google Scholar
- Edgerton VR, Roy RR, Apor P (1986) Specific tension of human elbow flexor muscles. In: Saltin B (ed) Biochemistry of exercise VI. Human Kinetics, Champaign, pp 487–500Google Scholar
- Goto K, Nagasawa M, Yanagisawa O, Kizuka T, Ishii N, Takamatsu K (2004) Muscular adaptations to combinations of high- and low-intensity resistance exercises. J Strength Cond Res 18:730–737Google Scholar
- Goto K, Ishii N, Kizuka T, Takamatsu K (2005) The impact of metabolic stress on hormonal responses and muscular adaptations. Med Sci Sports Exerc 37:955–963Google Scholar
- Häkkinen K, Newton RU, Gordon SE, McCormick M, Volek JS, Nindl BC, Gotshalk LA, Campbell WW, Evans WJ, Häkkinen A, Humphries BJ, Kraemer WJ (1998) Changes in muscle morphology, electromyographic activity, and force production characteristics during progressive strength training in young and older men. J Gerontol A Biol Sci Med Sci 53:415–423CrossRefGoogle Scholar
- Kaufman MP, Forster HV (1996) Reflexes controlling circulatory, ventilatory and airway responses to exercise. In: Rowell LB, Shepherd JT (eds) Handbook of physiology section 12: exercise: regulation and integration of multiple systems. Oxford University Press, New York, pp 381–447Google Scholar
- Kraemer WJ, Adams K, Cafarelli E, Dudley GA, Dooly C, Feigenbaum MS, Fleck SJ, Franklin B, Fry AC, Hoffman JR, Newton RU, Potteiger J, Stone MH, Ratamess NA, Triplett-McBride T (2002) American College of Sports Medicine. American College of Sports Medicine position stand. Progression models in resistance training for healthy adults. Med Sci Sports Exerc 34:364–380CrossRefGoogle Scholar
- Moritani T, deVries HA (1979) Neural factors versus hypertrophy in the time course of muscle strength gain. Am J Phys Med 58:115–130Google Scholar
- Nalbandian M, Takeda M (2016) Lactate as a signaling molecule that regulates exercise-induced adaptations. Biology (Basel) 5(4):38Google Scholar
- Rooney KJ, Herbert RD, Balnave RJ (1994) Fatigue contributes to the strength training stimulus. Med Sci Sports Exerc 26:1160–1164Google Scholar
- Sale D, MacDougall D (1981) Specificity in strength training: a review for the coach and athlete. Can J Appl Sport Sci 6:87–92Google Scholar
- Shimano T, Kraemer WJ, Spiering BA, Volek JS, Hatfield DL, Silvestre R, Vingren JL, Fragala MS, Maresh CM, Fleck SJ, Newton RU, Spreuwenberg LP, Häkkinen K (2006) Relationship between the number of repetitions and selected percentages of one repetition maximum in free weight exercises in trained and untrained men. J Strength Cond Res 20:819–823Google Scholar