Core Exercise as Non-Pharmacological Strategy for Improving Metabolic Health in Prediabetic Women

Abstract

Background and Objectives: Prediabetes (PD) is characterized by impaired glucose metabolism and is associated with an elevated risk of type 2 diabetes and cardiovascular diseases. This study aimed to investigate the effects of an 8-week core exercise intervention on glycemic control, lipid profiles, insulin sensitivity, body composition, and physical performance in prediabetic women. Materials and Methods: Eighteen prediabetic women aged 20-55 years were randomly allocated to either a core exercise group (n = 9) or a control group (n = 9). The intervention group completed 24 supervised core exercise sessions over 8 weeks, whereas the control group remained sedentary. Pre- and post-intervention evaluations included anthropometric measurements, flexibility and strength tests, fasting and postprandial glucose levels, HbA1c, insulin, HOMA-IR, lipid profiles, and serum iron levels. Non-parametric tests were used for statistical analysis, and a Principal Component Analysis (PCA) and hierarchical clustering were conducted to explore multidimensional metabolic changes. Results: Core exercise significantly improved the body weight, BMI, fat percentage, and circumferences (shoulder, chest, and hip), along with an enhanced flexibility and back-leg strength (p < 0.05). Glycemic indices (FBG, PBG, and HbA1c), insulin, and HOMA-IR levels were significantly reduced, while serum iron and HDL-C increased (p < 0.05). Lipid markers, including the TG, LDL-C, CHOL, and TG/HDL-C ratio, showed significant improvements. The PCA and cluster analyses identified three clusters reflecting metabolic risk, body composition, and protective factors. Conclusions: This study demonstrates that an 8-week structured core exercise program significantly improves glycemic control, lipid profiles, insulin sensitivity, and body composition in women with prediabetes. Multivariate analyses (PCA and hierarchical clustering) corroborate a metabolic shift towards a reduced insulin resistance and a more favorable cardiometabolic profile, supporting core training as a viable, evidence-based non-pharmacological intervention to mitigate metabolic risk.

Keywords: body composition; core training; glycemic control; insulin resistance; lipid profile; prediabetes.

Figure 1

Illustrates the study design, including the participant characteristics, assessment protocols, and core exercise intervention.

Figure 2

Changes in anthropometric parameters among individuals with prediabetes following the intervention are illustrated. Measurements include body mass (A), body mass index (BMI; (B)), shoulder circumference (C), chest circumference (D), waist circumference (E), hip circumference (F), body fat mass (G), and body muscle mass (H). The x-axis represents pre-test and post-test measurements, with post-test values statistically analyzed between the C and core exercise (Core Exer.) groups using an independent sample t-test. Horizontal lines above the bars indicate within-group differences over time. C: control group, Core Exer: core exercise group, ns: no significant difference, * p < 0.05, ** p < 0.01, and *** p < 0.001.

Figure 3

Changes in physical performance test outcomes among individuals with prediabetes following the intervention are illustrated. Measurements include right and left handgrip strength (A,B), back-leg strength (C) and flexibility score (D). The x-axis represents pre-test and post-test measurements, with post-test values compared between the C and Core Exer. groups using an independent sample t-test. Horizontal lines above the bars denote within-group differences observed between pre- and post-test values. C: control group, Core Exer: core exercise group, ns: no significant difference, and * p < 0.05.

Figure 4

Changes in glycemic and insulin resistance markers among individuals with prediabetes following the intervention are illustrated. Measurements include fasting blood glucose (FBG; (A)), postprandial blood glucose (PBG; (B)), hemoglobin A1c (HbA1c; (C)), iron (D), insulin (E), and homeostatic model assessment of insulin resistance (HOMA-IR; (F)). The x-axis represents pre-test and post-test measurements, with post-test values compared between the C and Core Exer. groups using an independent sample t-test. Horizontal lines above the bars indicate significant within-group differences over time. C: control group, Core Exer: core exercise group, * p < 0.05, ** p < 0.01, and *** p < 0.001.

Figure 5

Changes in plasma lipid profiles among individuals with prediabetes following the intervention are illustrated. Measurements include low-density lipoprotein cholesterol (LDL-C; (A)), high-density lipoprotein cholesterol (HDL-C; (B)), triglycerides (TG; (C)), total cholesterol (CHOL; (D)), and atherogenic index of plasma (AIP; (E)). The x-axis represents pre-test and post-test measurements, with post-test values compared between the C and Core Exer. groups using an independent sample t-test. Horizontal lines above the bars highlight within-group variations from pre- to post-test. C: control group, Core Exer: core exercise group, * p < 0.05, and ** p < 0.01.

Figure 6

The hierarchical clustering of metabolic risk factors, cardiometabolic protective factors, and anthropometric parameters among individuals with prediabetes following the intervention is illustrated. Different colored lines indicate distinct clusters (A, B, and C). Cluster A includes metabolic risk factors, such as CHOL, LDL-C, AIP, TG, HOMA-IR, insulin, FBG, PBG, HbA1c, and chest circumference. Cluster B includes body composition parameters, including the BMI, body mass, hip circumference, body fat mass, shoulder width, body muscle mass, and waist circumference. Cluster C comprises cardiometabolic protective factors, specifically HDL-C and iron.

Figure 7

The Principal Component Analysis (PCA) biplot illustrating the metabolic and cardiometabolic changes among individuals with prediabetes following intervention. The orange zone (pre-test) clusters participants with elevated metabolic risk markers, including HbA1c, FBG, PBG, HOMA-IR, insulin, CHOL, LDL-C, TG, and AIP, indicating a profile associated with insulin resistance and dyslipidemia. Following the intervention, participants transition towards the blue zone (post-test), characterized by increased HDL-C and iron levels. Each participant’s position is represented by green-tailed spheres. Red vectors represent the contribution of each metabolic parameter to the principal components. The transition from the orange to the blue zone indicates a beneficial metabolic adaptation induced by core exercise. As only the core exercise group received the intervention, the PCA was restricted to this group, thereby ensuring analytical precision by excluding the untreated C group.