Muscle Work and Its Relationship with ACE and ACTN3 Polymorphisms Are Associated with the Improvement of Explosive Strength

Background: The potential influence of genetics in athletic performance allows the search for genetic profiles associated with muscular work for the orientation of strength training and sports selection. The purpose of the study was to analyze four muscular exercises for effectiveness in improving explosive strength variables, associated to the genetics in Angiotensin Converting Enzyme (ACE) and α-actinin-3 (ACTN3) polymorphisms. Methods: A randomized controlled trial was conducted on a sample of 80 subjects allocated into four groups: concentric muscle work (CMW), eccentric muscle work (EMW), concentric-eccentric muscle (C-EMW) work and isometric muscular work (IMW), by block and gender randomization. Vertical jump, long jump, power jump, and speed were measured to study explosive strength. Genotypic frequencies of ACE (rs4646994) and ACTN3 (rs1815739) were obtained by polymerase chain reaction. Results: ACE gen showed significant improvements regarding the DD genotype in the Sargent test (p = 0.003) and sprint velocity test (p = 0.017). In the ACTN3 gene, the RR variable obtained improvement results with regard to RX and XX variables in long jump (p < 0.001), Sargent test (p < 0.001) and power jump (p = 0.004). Conclusions: The selected genes demonstrated an influence on the muscle work and the improvement in explosive strength variables with a decisive role regarding the type of muscle work performed.

Supramaximal Eccentric Training for Alpine Ski Racing—Strength Training with the Lifter

Eccentric muscular work plays a large role in alpine ski racing. Training with supramaximal eccentric loads (SME) is highly effective to improve eccentric strength but potentially dangerous. Most SME training devices do not allow the athlete to move a barbell freely as they would when performing conventional barbell training. The Intelligent Motion Lifter (IML) allows for safe SME training with a free barbell and no spotters. The IML can be used for free barbell training: a spotter for normal training, eccentric only, concentric only, and squat jumps. It is also a training and testing device for isokinetic and isometric exercise. This commentary addresses the necessity of eccentric training for elite alpine ski racers, the development of the IML and its use in training.

CHANGES IN THE STRUCTURAL AND FUNCTIONAL ORGANIZATION OF THE HEART UNDER THE INFLUENCE OF SYSTEMATIC PHYSICAL LOADS

Echocardiographic examination of 28 untrained and 11 trained young men aged 18-20 was performed. It has been shown that long-term systematic muscular work of significant volume and power contributes to the formation of a specific transformation of structures and functions of the heart with a high degree of lability aimed at ensuring the optimal form of adaptation to muscular work. The significant influence of a combination of systematic physical and psycho-emotional loads on the nature of these changes is proved. There is a clear functional dependence between the level of functional fitness of the body and indicators of structural and functional organization of the heart, namely: the deterioration of these indicators is accompanied by a marked decrease in functional fitness (level of physical performance and maximum oxygen consumption).

Kinesiotaping Diminishes Delayed Muscle Soreness but does not Improve Muscular Performance

This study aimed at determining the effect of kinesio-taping (KT) on muscle performance and delayed onset muscle soreness (DOMS) after exercise induced muscle damaged. Sixty-six healthy men volunteered to participate (age:18–25 y/o), who performed 200 isokinetic lengthening contractions of the dominant quadriceps. Then subjects were randomized to either control (no treatment), sham (no tape tension), or KT (10% tape tension) groups. Muscle performance was assessed by peak torque and muscular work during maximal isometric and concentric isokinetic contractions. DOMS intensity was assessed using a visual analog scale. Measurements were taken pre-exercise (Pre), 48 h and 96 h post-exercise. Repeated measures ANOVA was used for comparisons within group, and ANCOVA for comparisons among groups. Muscle damage was confirmed in all participants by an increase in CK activity level (p<0.01). Decrease in isometric and isokinetic peak torque was detected at 48 h in the control and sham groups (p<0.01). Muscular work decreased in all groups at 48 h (p<0.01). No differences between groups were detected in muscular performance variables. Increase in DOMS intensity was determined in all groups at 48 h. Comparisons between groups showed lower DOMS intensity in the KT group at 48 h. KT decreased DOMS intensity perception after exercise-induced muscle damage; however, it did not impact muscular performance.

Hyperoxia and hypoxia influence to adaptive processes at muscular work

In this brief review we will state the use of hyperoxia (HO) in sports training. HO training has been recommended by some authors for athletes to increase their performance. Herewith, there is no reliable knowledge about physiology mechanisms that provides the athlete level of growth during long-term training under HO conditions. Concurrently in the last half century, the athletes’ performance in endurance sports has grown remarkably due to natural and artificial hypoxia application in training process of many kinds of sports. Long-term adaptation mechanisms to muscular work under hypoxia conditions are shortly summarized for comparison with HO effects and we emphasized that the prospectivity of searching the ways for regular usage HO to increase athletic performance is too questionable.

Biomechanics Potential of the Masseter and Temporal Muscles in the Mandibles of Mesofacial Subjects

Introduction The knowledge of the organization of the masseter muscle (MM) and the temporal muscle (TM) is extremely important when related to the study of the stomatognathic system. Moreover, some authors have shown that mastication is of great importance, not only for the intake of food but also for the systemic, mental and physical functions of the body. Materials and Methods We have decided to analyze the biomechanical potential (length of the force arm, muscular work and mechanical advantage) of the MM and TM in the mandibles of mesofacial subjects (n = 34). Results Our results show that the MM exhibits a better biomechanical potential than the TM (p = 0.0001). Conclusion With these data, orthodontists may develop a specific treatment plan and get better results, especially in cases of patients in whom the biomechanical pattern of the temporomandibular joint is unfavorable.