Analysis of Contractile Properties in Gastrocnemius, Tibialis Anterior Muscle of Amateur Male Soccer Players Using Tensiomyography

BACKGROUND@#Tensiomyography (TMG) is a relatively new technique that assesses the contractile properties of muscles in response to a single electrical stimulus. This study aimed to evaluate the contractile properties of the gastrocnemius and tibialis anterior (TA) muscles in amateur soccer players using TMG.@*METHODS@#We recruited 41 male soccer players (high school group, n=21; college group, n=20). The gastrocnemius medialis (GM), gastrocnemius lateralis (GL), and TA muscles of both lower extremities were assessed using TMG. The maximal displacement (Dm), delay time, contraction time (Tc), sustained time, and half-relaxation time were obtained and compared between the two groups.@*RESULTS@#First, both groups showed low Dm for the GM and TA muscles, which indicated high stiffness of the muscle tone. Second, the Tc and contraction velocity (Vc) were high for all muscles, except for the GL showing lower speed than the other muscles, which represented the sports-specific characteristics of the soccer players. Third, there were no significant differences in the measurement variables between the dominant and non-dominant sides, except for the Tc of the GM in high school athletes and Vc of the TA in college athletes.@*CONCLUSIONS@#These results reflected the sports-specific needs and characteristics of soccer players. A risk of injury is associated with a high degree of stiffness, and various methods for preventing it should be considered.

Analysis of Contractile Properties in Gastrocnemius, Tibialis Anterior Muscle of Amateur Male Soccer Players Using Tensiomyography

BACKGROUND: Tensiomyography (TMG) is a relatively new technique that assesses the contractile properties of muscles in response to a single electrical stimulus. This study aimed to evaluate the contractile properties of the gastrocnemius and tibialis anterior (TA) muscles in amateur soccer players using TMG. METHODS: We recruited 41 male soccer players (high school group, n=21; college group, n=20). The gastrocnemius medialis (GM), gastrocnemius lateralis (GL), and TA muscles of both lower extremities were assessed using TMG. The maximal displacement (Dm), delay time, contraction time (Tc), sustained time, and half-relaxation time were obtained and compared between the two groups. RESULTS: First, both groups showed low Dm for the GM and TA muscles, which indicated high stiffness of the muscle tone. Second, the Tc and contraction velocity (Vc) were high for all muscles, except for the GL showing lower speed than the other muscles, which represented the sports-specific characteristics of the soccer players. Third, there were no significant differences in the measurement variables between the dominant and non-dominant sides, except for the Tc of the GM in high school athletes and Vc of the TA in college athletes. CONCLUSIONS: These results reflected the sports-specific needs and characteristics of soccer players. A risk of injury is associated with a high degree of stiffness, and various methods for preventing it should be considered.

Ursolic acid supplementation decreases markers of skeletal muscle damage during resistance training in resistance-trained men: a pilot study

Ursolic acid (UA) supplementation was previously shown to improve skeletal muscle function in resistance-trained men. This study aimed to determine, using the same experimental paradigm, whether UA also has beneficial effects on exercise-induced skeletal muscle damage markers including the levels of cortisol, B-type natriuretic peptide (BNP), myoglobin, creatine kinase (CK), creatine kinase-myocardial band (CK-MB), and lactate dehydrogenase (LDH) in resistance-trained men. Sixteen healthy participants were randomly assigned to resistance training (RT) or RT+UA groups (n=8 per group). Participants were trained according to the RT program (60~80% of 1 repetition, 6 times/week), and the UA group was additionally given UA supplementation (450 mg/day) for 8 weeks. Blood samples were obtained before and after intervention, and cortisol, BNP, myoglobin, CK, CK-MB, and LDH levels were analyzed. Subjects who underwent RT alone showed no significant change in body composition and markers of skeletal muscle damage, whereas RT+UA group showed slightly decreased body weight and body fat percentage and slightly increased lean body mass, but without statistical significance. In addition, UA supplementation significantly decreased the BNP, CK, CK-MB, and LDH levels (p<0.05). In conclusion, UA supplementation alleviates increased skeletal muscle damage markers after RT. This finding provides evidence for a potential new therapy for resistance-trained men.

Ursolic Acid-Induced Elevation of Serum Irisin Augments Muscle Strength During Resistance Training in Men

Ursolic acid (UA), a type of pentacyclic triterpenoid carboxylic acid purified from natural plants, can promote skeletal muscle development. We measured the effect of resistance training (RT) with/without UA on skeletal muscle development and related factors in men. Sixteen healthy male participants (age, 29.37+/-5.14 years; body mass index=27.13+/-2.16 kg/m2) were randomly assigned to RT (n=7) or RT with UA (RT+UA, n=9) groups. Both groups completed 8 weeks of intervention consisting of 5 sets of 26 exercises, with 10~15 repetitions at 60~80% of 1 repetition maximum and a 60~90-s rest interval between sets, performed 6 times/week. UA or placebo was orally ingested as 1 capsule 3 times/day for 8 weeks. The following factors were measured pre-and post-intervention: body composition, insulin, insulin-like growth factor-1 (IGF-1), irisin, and skeletal muscle strength. Body fat percentage was significantly decreased (p<0.001) in the RT+UA group, despite body weight, body mass index, lean body mass, glucose, and insulin levels remaining unchanged. IGF-1 and irisin were significantly increased compared with baseline levels in the RT+UA group (p<0.05). Maximal right and left extension (p<0.01), right flexion (p<0.05), and left flexion (p<0.001) were significantly increased compared with baseline levels in the RT+UA group. These findings suggest that UA-induced elevation of serum irisin may be useful as an agent for the enhancement of skeletal muscle strength during RT.

Corrigendum to: Ursolic Acid-Induced Elevation of Serum Irisin Augments Muscle Strength During Resistance Training in Men

The original version of this article contained misspelled name of author. The name of Figueroa Arturo is replaced with Arturo Figueroa.

Effects of aged garlic extract and endurance exercise on skeletal muscle FNDC-5 and circulating irisin in high-fat-diet rat models

BACKGROUND/OBJECTIVES: Irisin, a newly identified hormone, is associated with energy homeostasis. We investigated whether aged garlic extract (AGE) and exercise training intervention could improve body weight, insulin sensitivity, skeletal muscle fibronectin domain containing protein 5 (FNDC-5) levels, and plasma irisin in high-fat diet (HFD). MATERIALS/METHODS: Male Sprague Dawley rats were fed a ND (normal diet, n = 5) or HFD (n = 28) for 6 weeks. After 6 weeks, all rats were divided into 5 groups for the next 4 weeks: ND, (normal diet, n = 5), HFD (high-fat diet, n = 7), HFDA (high-fat diet + aged garlic extract, n = 7), HFDE (high-fat diet + exercise, n = 7), and HFDEA (high-fat diet + exercise + aged garlic extract, n = 7). Exercise groups performed treadmill exercises for 15-60 min, 5 days/week, and AGE groups received AGE (2.86 g/kg, orally injected) for 4 weeks. RESULTS: Significant decreases in body weight were observed in the ND, HFDE, and HFDEA groups, as compared with the HFD group. Neither intervention affected the masses of the gastrocnemius muscle or liver. There were no significant differences in glucose levels across the groups. The homeostatic model assessments of insulin resistance were significantly higher in the HFD group, as compared with the ND, HFDA, HFDE, and HFDEA groups. However, skeletal muscle FNDC-5 levels and plasma irisin concentrations were unaffected by AGE or exercise in obese rats. AGE supplementation and exercise training did not affect skeletal muscle FNDC-5 or plasma irisin, which are associated with insulin sensitivity in obese rats. CONCLUSION: Our results suggest that the protection against HFD-induced increases in body fat/weight and insulin resistance that are provided by AGE supplementation and exercise training may not be mediated by the regulation of FNDC-5 or irisin.

Aged garlic extract enhances exercise-mediated improvement of metabolic parameters in high fat diet-induced obese rats

Aged garlic extract (AGE) is known to have a protective effect against immune system, endothelial function, oxidative stress and inflammation. We examined the effects of exercise with and without aged garlic extract administration on body weight, lipid profiles, inflammatory cytokines, and oxidative stress marker in high-fat diet (HFD)-induced obese rats. Forty-five Sprague-Dawley rats were fed either a HFD (HFD, n = 40) or a normal diet (ND, n = 5) for 6 weeks and thereafter randomized into ND (n = 5), HFD (n = 10), HFD with AGE (n = 10), HFD with Exercise (n = 10), or HFD with Exercise+AGE (n = 10) for 4 weeks. AGE groups were administered at a dose of 2.86 g/kg.body weight, orally. Exercise consisted of running 15-60 min 5 days/week with gradually increasing intensity. AGE (P < 0.01), Exercise, and Exercise+AGE (P < 0.001) attenuated body weight gain and food efficiency ratio compared to HFD. Visceral fat and liver weight gain were attenuated (P < 0.05) with all three interventions with a greater effect on visceral fat in the Exercise+AGE than AGE (P < 0.001). In reducing visceral fat (P < 0.001), epididymal fat (P < 0.01) and liver weight (P < 0.001), Exercise+AGE was effective, but exercise showed a stronger suppressive effect than AGE. Exercise+AGE showed further additive effects on reducing visceral fat and liver weight (P < 0.001). AGE significantly attenuated the increase in total cholesterol and low-density lipoprotein-cholesterol compared with HFD (P < 0.05). Exercise+AGE attenuated the increase in triglycerides compared with HFD (P < 0.05). Exercise group significantly decrease in C-reactive protein (P < 0.001). These results suggest that AGE supplementation and exercise alone have anti-obesity, cholesterol lowering, and anti-inflammatory effects, but the combined intervention is more effective in reducing weight gain and triglycerides levels than either intervention alone.