Estudios científicos sobre hipertrofia
Haciendo un breve resumen lo que queda en claro es lo siguiente:
Frecuencia: no hay practicamente diferencias en el incremento de la masa muscular magra entre entrenar un grupo muscular dos veces por semana y tres veces por semana. Sin embargo si comparamos dos-tres veces por semana con una vez por semana, se nota casi el doble de incremento masa muscular magra en el primer caso contra el segundo.
Intensidad: este repaso apoya la recomendación tipica de entrenar con cargas del 70%-85% de 1RM cuando entrenamos para hipertrofia, pero también se ve marcada hipertrofia con mas pesadas y livianas cargas.
Volumen: moderado volumen dan gran respuesta hipertrofica (aproximadamente entre 30 y 60 repeticiones), mas alla de estos número la respuesta disminuye.
Descanso (entre series): este repaso de estudios apoya la utilizacion de generosos descansos entre series, para permitir esfuerzos cercanos al maximo.
Sports Med. 2007;37(3):225-64.
The influence of frequency, intensity, volume and mode of strength training on whole muscle cross-sectional area in humans.
Wernbom M, Augustsson J, Thomee R.
Lundberg Laboratory for Human Muscle Function and Movement Analysis, Department of Orthopaedics, Sahlgrenska University Hospital, Goteborg University, Goteborg, Sweden.
Strength training is an important component in sports training and rehabilitation. Quantification of the dose-response relationships between training variables and the outcome is fundamental for the proper prescription of resistance training. The purpose of this comprehensive review was to identify dose-response relationships for the development of muscle hypertrophy by calculating the magnitudes and rates of increases in muscle cross-sectional area induced by varying levels of frequency, intensity and volume, as well as by different modes of strength training.Computer searches in the databases MEDLINE, SportDiscus((R)) and CINAHL((R)) were performed as well as hand searches of relevant journals, books and reference lists. The analysis was limited to the quadriceps femoris and the elbow flexors, since these were the only muscle groups that allowed for evaluations of dose-response trends. The modes of strength training were classified as dynamic external resistance (including free weights and weight machines), accommodating resistance (e.g. isokinetic and semi-isokinetic devices) and isometric resistance. The subcategories related to the types of muscle actions used. The results demonstrate that given sufficient frequency, intensity and volume of work, all three types of muscle actions can induce significant hypertrophy at an impressive rate and that, at present, there is insufficient evidence for the superiority of any mode and/or type of muscle action over other modes and types of training. Tentative dose-response relationships for each variable are outlined, based on the available evidence, and interactions between variables are discussed. In addition, recommendations for training and suggestions for further research are given.
Excerpts From the Discussion
For quadriceps training with dynamic external resistance, the largest rate of gain in CSA (0.55% per day) was noted in the study with the greatest training frequency (12 sessions per week). However, it should be noted that (i) this study lasted for only 2 weeks; (ii) the intensity was 20% of 1RM; and (iii) the training was performed in combination with partial vascular occlusion. Therefore, the results from this study should be viewed with caution when considering the application of extremely high frequencies in more conventional training. Furthermore, it is interesting to note that there was no training difference in the mean rates of increase in CSA between two and three sessions per week for DER.
For elbow flexor training with dynamic external resistance, the greatest rate of increase in CSA (0.59% per day; 17.7% total increase in CSA) was observed in a study with a frequency of four times a week. The second, third, fourth highest increase in CSA rates noted were 0.42%, 0.38% and 0.32% per day, respectively. These three studies[125,126,132] used a frequency of three times per week. However, with the exception of these three studies, the average values suggest that there is relatively little difference between training the elbow flexors two or three times per week, in terms of the rate of increase in CSA (0.18% per day for both frequencies).
The results of Vikne et al. and Wirth et al. are remarkably similar despite using different muscle groups and training modes. In both reports, two and three sessions per week yielded almost twice the increase in muscle CSAwhen compared with one session, with no apparent further advantage for three versus two sessions.
Thus, the results of this review support the typical recommendations with intensity levels of 70–85% of maximum when training for muscle hypertrophy, but also show that marked hypertrophy is possible at both higher and lower loads.
That said, figure 11, for the total repetitions for DER training of the elbow flexors, suggests a dose-response curve where greater gains in muscle muscle thickness were demonstrated with increasing volume (or duration) of work, but with diminishing returns as the volume increases further. Overall, moderate volumes (≈30–60 repetitions per session for DER training) appear to yield the largest responses.
Upon closer examination, it appears that when maximal or near-maximal efforts are used, it is advantageous to use long periods of rest. This is logical in light of the well known detrimental effects of fatigue on force production and electrical activity in the working muscle. If high levels of force and maximum recruitment of motor units are important
factors in stimulating muscle hypertrophy, it makes sense to use generous rest periods between sets and repetitions of near-maximal to maximal efforts.
Bueno este otro clasico entre estudios, la comparación entre 1 serie vs multiples series (en este caso 3), en relación a ganancias de fuerza y masa muscular. El resultado para los que no hablan ingles fue el siguiente:
Para la parte superior del cuerpo no hubo diferencias entre 1 vs. Multiples series, pero si lo hubo para la parte inferior 41% vs 21% de aumento de masa muscular a favor de multiples series.
J Strength Cond Res. 2007 Feb;21(1):157-63. Related Articles
Dissimilar effects of one- and three-set strength training on strength and muscle mass gains in upper and lower body in untrained subjects.
Ronnestad BR, Egeland W, Kvamme NH, Refsnes PE, Kadi F, Raastad T.
Ronnestad, B.R., W. Egeland, N.H. Kvamme, P.E. Refsnes, F. Kadi, and T. Raastad. Dissimilar effects of one- and three-set strength training on strength and muscle mass gains in upper and lower body in untrained subjects. J. Strength Cond. Res. 21(1):157-163. 2007.-The purpose of this study was to compare the effects of single- and multiple-set strength training on hypertrophy and strength gains in untrained men. Twenty-one young men were randomly assigned to either the 3L-1UB group (trained 3 sets in leg exercises and 1 set in upper-body exercises; n = 11), or the 1L-3UB (trained 1 set in leg exercises and 3 sets in upper-body exercises; n = 10). Subjects trained 3 days per week for 11 weeks and each workout consisted of 3 leg exercises and 5 upper-body exercises. Training intensity varied between 10 repetition maximum (RM) and 7RM. Strength (1RM) was tested in all leg and upper-body exercises and in 2 isokinetic tests before training, and after 3, 6, 9, and 11 weeks of training. Cross sectional area (CSA) of thigh muscles and the trapezius muscle and body composition measures were performed before training, and after 5 and 11 weeks of training. The increase in 1RM from week 0 to 11 in the lower-body exercises was significantly higher in the 3L-1UB group than in the 1L-3UB group (41 vs. 21%; p < 0.001), while no difference existed between groups in upper-body exercises. Peak torque in maximal isokinetic knee-extension and thigh CSA increased more in the 3L-1UB group than in the 1L-3UB group (16 vs. 8%; p = 0.03 and 11 vs. 7%; p = 0.01, respectively), while there was no significant difference between groups in upper trapezius muscle CSA. The results demonstrate that 3-set strength training is superior to 1-set strength training with regard to strength and muscle mass gains in the leg muscles, while no difference exists between 1- and 3-set training in upper-body muscles in untrained men.