Relationship between fat-free mass index and nutrient intake in protein supplement user among Japanese collegiate soccer athletes.

Purpose: Protein supplements are widely used by athletes, prompting the scrutiny of their impact on low energy availability. This study investigated whether habitual protein supplement use is linked to physical characteristics and nutrient intake in Japanese university soccer athletes. In addition, an attempt was made to examine the differences in physical characteristics and nutrient intake according to muscle mass in protein supplement users using the fat-free mass index (FFMI), which reflects muscle mass.

Continuous training in young athletes decreases hepcidin secretion and is positively correlated with serum 25(OH)D and ferritin.

Background: Iron deficiency is known to impair muscle function and reduce athletic performance, while vitamin D has been reported to induce iron deficiency. However, the mechanism underlying exercise-induced changes in iron metabolism and the involvement of vitamins in this mechanism are unclear. The present study examined changes in biological iron metabolism induced by continuous training and the effects of vitamin D on these changes.

Skeletal muscle metabolic dysfunction with circulating carboxymethyl-lysine in dietary food additive-induced leaky gut.

Impaired intestinal permeability induces systemic inflammation and metabolic disturbance. The effect of a leaky gut on metabolism in skeletal muscle, a major nutrient consumer, remains unclear. In this study, we aimed to investigate the glucose metabolic function of the whole body and skeletal muscles in a mouse model of diet-induced intestinal barrier dysfunction.

High-intensity exercise impairs intestinal barrier function by generating oxidative stress.

The intestine functions as a barrier preventing the entry of extrinsic factors into the body. This barrier function is disrupted by oxidative damage along with an impaired mucosal layer. Excessive exercise can generate oxidative stress in the intestinal tissue; however, the effect of exercise-induced oxidative stress on intestinal permeability is unclear.

Matcha green tea beverage moderates fatigue and supports resistance training-induced adaptation.

Background: Resistance training adaptively increases muscle strength and mass, contributing to athletic performance and health promotion. Dietary intervention with natural foods provides nutrients that help accelerate muscle adaptation to training. Matcha green tea contains several bioactive factors such as antioxidants, amino acids, and dietary fibers; however, its effect on muscle adaptation is unclear.