Effect of Repetition Duration—Total and in Different Muscle Actions—On the Development of Strength, Power, and Muscle Hypertrophy

Despite the intensive investigation of the molecular mechanism of skeletal muscle hypertrophy, the underlying signaling processes are not completely understood. Therefore, we used an overload model, in which the main synergist muscles (gastrocnemius, soleus) of the plantaris muscle were surgically removed, to cause a significant overload in the remaining plantaris muscle of 8-month-old Wistar male rats. SIRT1-associated pro-anabolic, pro-catabolic molecular signaling pathways, NAD and H2S levels of this overload-induced hypertrophy were studied. Fourteen days of overload resulted in a significant 43% (p < 0.01) increase in the mass of plantaris muscle compared to sham operated animals. Cystathionine-β-synthase (CBS) activities and bioavailable H2S levels were not modified by overload. On the other hand, overload-induced hypertrophy of skeletal muscle was associated with increased SIRT1 (p < 0.01), Akt (p < 0.01), mTOR, S6 (p < 0.01) and suppressed sestrin 2 levels (p < 0.01), which are mostly responsible for anabolic signaling. Decreased FOXO1 and SIRT3 signaling (p < 0.01) suggest downregulation of protein breakdown and mitophagy. Decreased levels of NAD+, sestrin2, OGG1 (p < 0.01) indicate that the redox milieu of skeletal muscle after 14 days of overloading is reduced. The present investigation revealed novel cellular interactions that regulate anabolic and catabolic processes in the hypertrophy of skeletal muscle.

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Orbicularis Oculi Muscle Size and Function: Exploring the Influence of Aging and Exercise Training

Cosmetics ◽

10.3390/cosmetics8020029 ◽

2021 ◽

Vol 8 (2) ◽

pp. 29

Author(s):

Takashi Abe ◽

Jeremy P. Loenneke

Keyword(s):

Older Adults ◽

Exercise Training ◽

Muscle Hypertrophy ◽

Peak Velocity ◽

Muscle Thickness ◽

Muscle Size ◽

Sphincter Muscle ◽

Orbicularis Oculi Muscle ◽

Orbicularis Oculi ◽

And Function

The orbicularis oculi muscle is the sphincter muscle of the eyelids that blinks and closes the eyes. In this review, our aim was threefold: (1) to introduce the performance characteristics of blinking activity in young and older adults, (2) to discuss the influence of aging on the orbicularis oculi muscle in healthy adults, and (3) to provide information about the effect of facial exercise training on the orbicularis oculi muscle. To achieve the purpose of this review, a search using two electronic databases (PubMed and Scopus) and a search engine (Google Scholar) was conducted. The amplitude and peak velocity of spontaneously blinking behavior, which is an index of muscle function of the orbicularis oculi, appear to be affected by aging. The muscle thickness of the orbicularis oculi tends to be low in older adults, but there are issues that need to be examined further, such as differences in sex and measurement positions. There was no study on the effect of exercise training; however, the results of a highly trained man indicate that the orbicularis oculi muscles might elicit muscle hypertrophy through non-traditional resistance exercise.

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Are We Exploring the Potential Role of Specialized Techniques in Muscle Hypertrophy?

International Journal of Sports Medicine ◽

10.1055/a-1342-7708 ◽

2021 ◽

Author(s):

Witalo Kassiano ◽

Bruna Daniella de Vasconcelos Costa ◽

João Pedro Nunes ◽

Andreo Fernando Aguiar ◽

Belmiro F. de Salles ◽

...

Keyword(s):

Resistance Training ◽

Muscle Hypertrophy ◽

Potential Role ◽

Ecological Validity ◽

Trained Subjects ◽

Training Techniques ◽

Methodological Rigor ◽

Traditional Resistance Training ◽

Intervening Variables

AbstractSpecialized resistance training techniques (e.g., drop-set, rest-pause) are commonly used by well-trained subjects for maximizing muscle hypertrophy. Most of these techniques were designed to allow a greater training volume (i.e., total repetitions×load), due to the supposition that it elicits greater muscle mass gains. However, many studies that compared the traditional resistance training configuration with specialized techniques seek to equalize the volume between groups, making it difficult to determine the inherent hypertrophic potential of these advanced strategies, as well as, this equalization restricts part of the practical extrapolation on these findings. In this scenario, the objectives of this manuscript were 1) to present the nuance of the evidence that deals with the effectiveness of these specialized resistance training techniques and — primarily — to 2) propose possible ways to explore the hypertrophic potential of such strategies with greater ecological validity without losing the methodological rigor of controlling possible intervening variables; and thus, contributing to increasing the applicability of the findings and improving the effectiveness of hypertrophy-oriented resistance training programs.

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