Journal of Exercise & Organ Cross Talk

Abstract Incretin–based therapies and protein-based dietary strategies represent two increasingly prominent approaches for fat loss in individuals with obesity, including those who engage in structured exercise. Incretin–based therapies promote weight loss primarily through appetite suppression, delayed gastric emptying, and improvements in glycemic regulation, resulting in rapid and clinically meaningful reductions in body mass. In contrast, protein-focused interventions support fat loss through enhanced satiety, preservation of diet-induced thermogenesis, and direct stimulation of muscle protein synthesis, typically producing slower but more metabolically stable changes in body composition.

For physically active individuals, the interaction between these strategies and exercise introduces additional physiological considerations beyond total weight loss. Exercise, particularly resistance training, increases the demand for adequate substrate availability to support skeletal muscle maintenance, remodeling, and functional adaptation. Importantly, these approaches also differ in the temporal pattern of fat loss, the extent to which lean mass is affected, and the durability of weight loss once active intervention slows or ceases, factors that are especially relevant for individuals pursuing long-term exercise adherence and performance.

This review synthesizes current evidence on incretin–based therapies and protein-based dietary strategies through an exercise-relevant lens, focusing on three underexamined determinants: skeletal muscle preservation, pace of fat loss, and weight-loss maintenance. Rather than positioning these approaches as competing or hierarchical, the review aims to clarify what physiological trajectories individuals may encounter when integrating each strategy with exercise. Understanding these trajectories may help practitioners and physically active individuals make more informed, context-specific decisions when selecting fat-loss interventions.

Abstract Primary objective of this study was to examine the interplay between grip strength, a functional marker of hypertrophy, and its connection to the Firmicutes to Bacteroidetes ratio in the gut microbiome. Twenty-five male Wistar rats were divided into five groups using a computerized randomizer: old and young control groups (OC, YC), old resistance training group (OR), old supplement group (OS), and old resistance training combined with supplement group (ORS). Rats in the OR and ORS cohorts underwent eight weeks of ladder-climbing resistance training three times a week, while those in the OS group were given supplements 5 times per week after the intervention. Muscle samples were collected from all rats two days’ post-intervention. FOXO1, BAX, and cytochrome C, were assessed using PCR-real time. Analysis of the data was carried out using one-way ANOVA and post-hoc Tukey testing. The results revealed a decrease in FOXO1 and apoptotic gene expression post-intervention, with a more pronounced reduction observed in the ORS group compared to the other groups (p<0.05). Notably, supplementation alone did not impact FOXO1 expression, akin to the effect of exercise on cytochrome C. A moderate negative correlation was documented between the F/B ratio and grip strength (p= 0.003; r= -0.54). Additionally, positive and moderate correlations were observed between FOXO1, BAX, cytochrome C, and the F/B ratio (p<0.05). These findings emphasize a functional association between the gut microbiome and muscle through their metabolites, indicating mutual regulation. Furthermore, it is suggested that exercise and supplements may further enhance these interconnected mechanisms.

Abstract Aim of this study was to determine the relations among the tight junction (TJs) genes, muscle strength and cross-sectional area (CSA) influenced by resistance training with or without specific supplement (a combination of lactobacillus and bifidobacterium probiotics, leucine amino acid and Vitamin-D). For this purpose, 25 male wistar rats in two age groups (3 months in young control and 16-24 months in four other groups) randomly divided in 5 equal groups (old and young control, resistance training, supplement and resistance training plus supplement). After 8 weeks of resistance training trice a week and oral gavage of supplement 5 times per week there were no any relation between grip strength and muscle CSA with zonula occludens-1 (ZO-1) and occludin (Occ) genes. But result of one-way ANOVA revealed that there were significantly differences among study groups in TJs genes, muscle strength and CSA (P≤0.05). Our finding showed that resistance training along with supplement can increase the level of ZO-1 (P=0.011), and Occ genes (P=0.023) expression. Indeed, resistance training plus supplement had synergistic effect on muscle CSA and grip strength (P=0.001) that can be comparable with young group. In addition, supplement alone appears that doesn’t have beneficial impact on physical function but surprisingly our finding shows strong inverse correlation between Occ and grip strength (p=0.015, r= -1.0) in supplement group which implies that although supplement alone can’t improve physical function but can maintain intestinal barrier function.