Camila S Padilha1, Paola S Cella2, Alex S Ribeiro3, Fabrício A Voltarelli4, Mayra T J Testa2, Poliana C Marinello5, Kessi C Iarosz2, Philippe B Guirro2, Rafael Deminice2. 1. State University of Londrina, Department of Physical Education, Londrina, PR, Brazil. Electronic address: camilapersonal@yahoo.com.br. 2. State University of Londrina, Department of Physical Education, Londrina, PR, Brazil. 3. Center for Research in Health Sciences. University of Northern Paraná, Londrina, PR, Brazil. 4. Federal University of Mato Grosso, Department of Physical Education, Cuiabá, Brazil. 5. State University of Londrina, Department of Physical Education, Londrina, PR, Brazil; State University of Londrina, Department of General Pathology, Londrina, PR, Brazil.
Abstract
AIMS: The main aim of this study was to investigate the moderate versus high-load resistance training on muscle strength, hypertrophy and protein synthesis signaling in rats. METHODS: Twenty rats were randomly allocated into three groups as follow: control group (C, n = 6), high-load training (HL, n = 7) and moderate-load training (ML, n = 7). A ladder climb exercise was used to mimic resistance exercise. ML resistance training consisted of a moderate load, allowing performance at higher volume of load inherent to higher number of repetitions (8-16 climbing). HL resistance training consisted of progressively increase training load, with low volume of load (4-8 climbing). C group remained with physical activity restricted to their cage space. This experiment was conducted over a six-weeks period. Forty-eight hours after the last resistance training session the animals were euthanized for tissue collection. RESULTS: Both HL and ML regimens promoted similar increases in muscle strength, elevated protein synthesis signaling demonstrated by increased skeletal muscle total/phosphorylated P-70S6K ratio and similar increases in plantaris and FHL muscle hypertrophy, all compared to control. All these similarities were demonstrated even though testosterone/cortisol ratio was higher in HL group compared to ML and control. ML regimen caused higher total training volume and soleus muscle hypertrophy, which was not demonstrated in HL group. CONCLUSION: In conclusion, results suggest that both HL and ML induce muscle hypertrophy and increase on strength in a similar way. ML moreover seems to favor slow fiber hypertrophy due the higher training volume.
AIMS: The main aim of this study was to investigate the moderate versus high-load resistance training on muscle strength, hypertrophy and protein synthesis signaling in rats. METHODS: Twenty rats were randomly allocated into three groups as follow: control group (C, n = 6), high-load training (HL, n = 7) and moderate-load training (ML, n = 7). A ladder climb exercise was used to mimic resistance exercise. ML resistance training consisted of a moderate load, allowing performance at higher volume of load inherent to higher number of repetitions (8-16 climbing). HL resistance training consisted of progressively increase training load, with low volume of load (4-8 climbing). C group remained with physical activity restricted to their cage space. This experiment was conducted over a six-weeks period. Forty-eight hours after the last resistance training session the animals were euthanized for tissue collection. RESULTS: Both HL and ML regimens promoted similar increases in muscle strength, elevated protein synthesis signaling demonstrated by increased skeletal muscle total/phosphorylated P-70S6K ratio and similar increases in plantaris and FHL muscle hypertrophy, all compared to control. All these similarities were demonstrated even though testosterone/cortisol ratio was higher in HL group compared to ML and control. ML regimen caused higher total training volume and soleus muscle hypertrophy, which was not demonstrated in HL group. CONCLUSION: In conclusion, results suggest that both HL and ML induce muscle hypertrophy and increase on strength in a similar way. ML moreover seems to favor slow fiber hypertrophy due the higher training volume.
Authors: Mayra Tardelli de Jesus Testa; Paola Sanches Cella; Poliana Camila Marinello; Fernando Tadeu Trevisan Frajacomo; Camila de Souza Padilha; Patricia Chimin Perandini; Felipe Arruda Moura; José Alberto Duarte; Rubens Cecchini; Flavia Alessandra Guarnier; Rafael Deminice Journal: Front Oncol Date: 2022-07-01 Impact factor: 5.738