Six weeks of Jilin ginseng root supplementation attenuates drop jump-related muscle injury markers in healthy female college students

Eccentric muscle contraction is an inherent component of numerous sporting movements but can result in muscle fatigue and injury, especially when engaging in unfamiliar exercise, which requires pharmacological intervention.

Myostatin A55T Genotype is Associated with Strength Recovery Following Exercise-Induced Muscle Damage

Myostatin A55T genotype is one of the candidates showing inter-individual variation in skeletal muscle phenotypes. The aim of this study was to investigate the effect of the myostatin A55T genotype on markers of muscle damage after eccentric exercise. Forty-eight young, healthy male college students (age = 24.8 ± 2.2 years, height = 176.7 ± 5.3 cm, weight = 73.7 ± 8.3 kg) were enrolled in this study, and muscle damage was induced through 50 reps of maximal eccentric muscle contraction. As markers of muscle damage, maximal isometric strength (MIS), muscle soreness, creatine kinase (CK), and aspartate transaminase (AST) were measured. Myostatin A55T genotypes were classified into homozygous myostatin A55T allele (AA, n = 34, 72%), heterozygous myostatin A55T allele (AT, n = 13, 26%), and homozygous mutant carriers (TT, n = 1, 2%). After eccentric exercise, the subjects with heterozygous for AT showed markedly quicker MIS recovery compared to the AA group (p = 0.042). However, there were no significant variations in muscle soreness (p = 0.379), CK (p = 0.955), and AST (p = 0.706) among the groups. These results suggest that AT in myostatin A55T genotype may be associated with quicker strength recovery following exercise-induced muscle damage.

Physiology of Distinct Modes of Muscular Contraction

Physiological changes in musculature allow widespread movements in human body. Correspondingly, varying in muscle prototypes characterise direct different training paradigms in therapeutics practice or can governs athletic performances. Mode of muscle contraction type are isometric, concentric or eccentric. Great examples of concentric exercise are walking- up-hill, stair ascent and lifting a dumbbell in bicep curl or pushing a bar up. Examples of eccentric muscle actions are walking - down-hill, satire decent and, isokinetic arm and leg extensions. During isometric muscle contraction the length of muscle does not change while muscle exert force .This type of movement can be seen while a person performs a maximal voluntary contractions (MVCs).Eccentric exercises increasing the concentric and isometric contraction as well. Performing the eccentric muscle contraction in daily life enhance quality of life and lifespan due to increasing muscle strength with low cost of energy consuming and thus it can apply in variety of domains. A simple walking task such as downhill - walking (i.e. 30 min) can provide the aforementioned conditions.