Metabolic syndrome (MetS) is a multifactorial disorder characterized by insulin resistance, abdominal obesity, dyslipidemia, and hypertension, and is associated with an increased risk of type 2 diabetes and cardiovascular disease. Lifestyle modification, particularly combined resistance and aerobic training, is an effective strategy to improve metabolic health. Functional foods such as chia seeds (Salvia hispanica L.) may provide additional benefits; however, their combined effects with exercise on insulin resistance remain unclear. This study aimed to examine the effects of eight weeks of combined training with or without chia seed supplementation on indirect indices of insulin resistance in women with MetS.

In this semi-experimental study, 26 sedentary, non-menopausal women aged 40–52 years with MetS were randomly assigned to combined training alone (T, n = 13) or combined training plus chia seed supplementation (T+S, n = 13). Participants trained three times per week using resistance exercises (RPE 15–17) and aerobic exercise at 60–80% of heart rate reserve. The T+S group consumed 20 g/day of chia seeds. Fasting blood glucose, insulin, triglycerides, and HDL-C were measured before and after the intervention, and HOMA-IR, triglyceride–glucose index (TYG), TG/HDL, and TYG-BMI were calculated.

Both groups showed significant reductions in HOMA-IR, with no significant between-group differences. However, the T+S group demonstrated significantly greater reductions in TYG and TG/HDL. A significant positive correlation was observed between TYG and HOMA-IR. In conclusion, combined training significantly improves insulin resistance in women with MetS, while chia seed supplementation may provide additional benefits for lipid-related insulin resistance markers.