Resistance exercise training augments the immunomodulatory adaptations to aerobic high-intensity interval training.

To compare the effectiveness of different types of high-intensity interval training (HIIT) on meta-inflammation during obesity, TLR4 pathway activities were assessed following a 10-week randomized trial. 30 young females with overweight and obesity were randomly allocated to aerobic HIIT (HIIT/AE) or resistance exercise in HIIT (HIIT/RE) and performed a 28-minute (4 × 4 min) in each session. During each interval, the HIIT/AE performed four minutes of all-extremity cycling, whereas the HIIT/RE completed four minutes of combined resistance exercises and all-extremity cycling. The TLR4 pathway gene expression was measured for the TLR4 receptor, downstream adaptors (TIR domain-containing adaptor-inducing interferon-β (TRIF) and myeloid differentiation factor (MYD) 88), transcriptional factors (nuclear factor kappa B (NF-κB), and interferon regulatory factor (IRF) 3), and its negative regulator (tumor necrosis factor (TNF) a-induced protein 3 (TNFAIP3)). The serum levels of TNFα, interferon (IFN) γ, interleukin (IL)-10, and adiponectin were measured. We found that TLR4 (HIIT/RE: 0.6 ± 0.43 vs. HIIT/AE: 1.24 ± 0.82, p = 0.02), TRIF (HIIT/RE: 0.51 ± 0.4 vs. HIIT/AE: 3.56 ± 0.52, p = 0.001), and IRF3 (HIIT/RE: 0.49 ± 0.42 vs. HIIT/AE: 0.6 ± 0.89; p = 0.04) levels were significantly downregulated in HIIT/RE compared to the HIIT/AE, with a significant reduction in serum levels of TNFα (pg/ml) (HIIT/RE: 22.5 ± 11.3 to 6.3 ± 5.3 vs. HIIT/AE: 19.16 ± 20.8 to 13.48 ± 21.7, p = 0.04) and IFNγ (pg/ml) (HIIT/RE: 43.5 ± 20.6 to 37.5 ± 4.3 vs. HIIT/AE: 37.6 ± 5.6 to 68.1 ± 22.5, p = 0.03). Adiponectin and IL-10 levels did not significantly differ between the two groups. Thus, resistance exercise training augments the immunomodulatory adaptations to HIIT and should be prescribed to people at risk of cardiometabolic disease.Highlights HIIT in combination with resistance exercise looks more effective than HIIT alone to target TLR4-mediated inflammation in individuals with overweight and obesity.HIIT/RE induces a different effect on two downstream cascades of TLR4, leading to a greater overall reduction of TRIF-dependent pathway activities compared to MYD88.Both HIIT protocols show comparable effects on the negative regulatory protein TNFAIP3 gene expression.