The prevalence of metabolic syndrome (MS) has been rapidly increasing in both developed and developing countries and is commonly associated with obesity [1].

MS is a multifactorial clinical condition characterized by a cluster of metabolic disturbances that include central obesity, insulin resistance, dyslipidemia, and arterial hypertension. This grouping of risk factors is associated with a significant increase in cardiovascular morbidity and mortality, as well as a higher risk of developing type 2 diabetes mellitus [2]. The global rise in MS parallels the growth of sedentary behavior and obesity, reflecting behavioral and environmental changes related to modern lifestyle [3].

It is estimated that approximately one-quarter of the world’s adult population meets the diagnostic criteria for MS, representing a major public health challenge [4]. Lifestyle-based interventions, particularly regular physical training, have been shown to be key strategies in preventing and treating this syndrome [5].

Considering the characteristics of this condition, one of the main treatments to reduce body weight and fat mass involves combining physical exercise with dietary re-education, as this strategy facilitates the establishment of a negative energy balance [6].

Physical exercise promotes several beneficial physiological and metabolic adaptations, among which the improvement of insulin sensitivity, increased energy expenditure and fatty acid oxidation, reduction of visceral adiposity, and positive modulation of inflammatory markers stand out [7]. Additionally, exercise training acts on molecular pathways such as AMPK, PI3K/Akt, and PGC-1α, stimulating mitochondrial biogenesis and reducing oxidative stress—central mechanisms in restoring metabolic homeostasis [8][9].

From a clinical perspective, evidence shows that structured exercise programs—whether aerobic, resistance, or combined—can significantly reduce abdominal circumference, blood pressure, fasting glucose, and triglyceride levels in individuals with MS [10][11]. These effects reinforce the role of physical training as a first-line intervention—safe, low-cost, and with a substantial impact on quality of life and cardiovascular prognosis [12].

Although the role of exercise in improving the components of metabolic syndrome is widely recognized, there are still gaps in the integrated understanding of the physiological and molecular mechanisms involved, as well as uncertainties regarding the most effective dose, intensity, and type of training for different patient profiles. Analyzing available clinical evidence, combined with elucidating the underlying mechanisms, is essential to guide personalized strategies for prevention and treatment.

To review the main clinical evidence and the physiological and molecular mechanisms associated with the effects of physical training on metabolic syndrome, highlighting the impacts on energy metabolism, insulin sensitivity, inflammatory profile, and cardiometabolic risk factors.

This is a narrative literature review aimed at synthesizing the main scientific evidence available on the effects of physical training on the clinical, physiological, and molecular aspects of MS. The literature search was conducted in the PubMed/MEDLINE, Scopus, ScienceDirect, and SciELO databases, including publications from 2010 to 2025.

The following English descriptors were used: metabolic syndrome, exercise training, physical activity, aerobic exercise, resistance training, insulin sensitivity, inflammation, and mitochondrial function. In Portuguese: síndrome metabólica, treinamento físico, atividade física, exercício aeróbico, exercício resistido, and inflamação sistêmica.

Inclusion criteria comprised original articles, systematic reviews, meta-analyses, and controlled clinical trials that investigated the effects of physical exercise on clinical parameters (blood pressure, body composition, glycemia, lipid profile) and physiological parameters (mitochondrial biogenesis, insulin sensitivity, inflammatory markers) in individuals with MS. Exclusion criteria were: studies exclusively with animal models, narrative reviews without a critical approach, articles without full-text access, and publications in languages other than Portuguese or English.

Study selection was conducted in three stages: title screening, abstract analysis, and full-text reading of eligible articles. Extracted information included: author and year, sample characteristics, type and duration of training, main clinical outcomes, and physiological mechanisms. Data were organized descriptively and interpretatively, allowing for an integrated discussion between clinical evidence and underlying physiological mechanisms.

Physical training is a fundamental therapeutic tool for the prevention and treatment of metabolic syndrome (MS), with well-established clinical and molecular benefits. Exercise-induced adaptations—especially through combined aerobic and resistance training—improve insulin sensitivity, reduce systemic inflammation, stimulate mitochondrial biogenesis, and promote metabolic homeostasis. At the molecular level, exercise regulates central metabolic pathways, including AMPK activation, PGC-1α expression, and GLUT4 signaling, contributing to energy balance and preventing metabolic dysfunctions associated with obesity and insulin resistance. Furthermore, regular physical activity exerts cardioprotective effects by modulating plasma lipids, blood pressure, and inflammatory markers—key components in reducing the elevated cardiovascular risk characteristic of individuals with MS.

Beyond these physiological effects, exercise prescription should follow structured, evidence-based guidelines. Current recommendations indicate that adults with MS should perform aerobic exercise 3 to 5 times per week at moderate to vigorous intensity, accumulating 150 - 300 minutes per week of moderate activity or 75 - 150 minutes of vigorous activity [39]. Resistance training is recommended 2 - 3 times per week, involving major muscle groups, with 1 - 3 sets of 8 - 12 repetitions. Combined training (aerobic + resistance) provides the greatest impact on visceral fat reduction, improved insulin sensitivity, and modulation of inflammatory markers [40]. High-intensity interval training (HIIT) may be incorporated for clinically stable individuals, offering superior improvements in cardiorespiratory fitness and glycemic control [41]. Exercise prescription should also be individualized, considering baseline fitness level, comorbidities, and patient preferences to optimize adherence and clinical outcomes [42].

Therefore, physical exercise should be considered a first-line, low-cost, and highly effective intervention with substantial public health impact. Strategies that promote regular participation—particularly when individualized and combined with nutritional guidance—can significantly reduce the incidence, progression, and complications associated with metabolic syndrome.

Despite their usefulness in synthesizing broad and heterogeneous evidence, narrative reviews present important limitations, particularly regarding the potential for selection bias. Because they do not follow strictly structured protocols—such as explicit inclusion and exclusion criteria, systematic assessment of methodological quality, or standardized search strategies—there is greater subjectivity in the choice of included studies [43][44]. This flexibility may result in disproportionate emphasis on certain findings, inadvertent exclusion of relevant studies, or overlapping interpretations influenced by the authors’ prior experience [45]. Additionally, the absence of quantitative methods to evaluate the consistency of results limits the strength of the conclusions and reduces reproducibility [46]. Thus, although useful for integrating knowledge and discussing physiological mechanisms, narrative reviews should have their conclusions interpreted with caution, acknowledging the inherent biases of this study design.