Dose-response Effects Of High-intensity Interval Neuromuscular Training On Musculoskeletal Fitness In Overweight And Obese Adults

Abstract

PURPOSE: The rising prevalence of overweight and obesity is considered a major public health issue negatively affecting more than one in two adults globally. Overweight and obese adults demonstrate lower musculoskeletal fitness levels compared to normoweight individuals resulting in reduced mobility, poor functional capacity, physical limitations, and increased injury risk during activities of daily living and exercise. METHODS: This study investigated the dose-response relationship between a 6-month interval neuromuscular training program (DoIT) and several musculoskeletal fitness parameters in previously inactive overweight and obese adults in a free-living environment. Ninety-seven middle-aged (44.8 ± 5.2 yrs) overweight or obese (31.2 ± 5.7 kg/m2) individuals (66% female) were randomly assigned to the following groups: (i) no-intervention control (CON, n = 29), (ii) DoIT performed once weekly (DoIT-1, n = 24), (iii) DoIT performed twice weekly (DoIT-2, n = 23) and (iv) DoIT performed thrice weekly (DoIT-3, n = 21). DoIT was a progressive, interval-type, multimodal exercise protocol using progressive functional resistance accessory training with prescribed work-to-rest intervals ranging from 1:3 to 2:1 in a circuit format (2–3 rounds). Muscular strength, muscular endurance, flexibility, and static balance were assessed at baseline and 6 months following intervention. RESULTS: At post-training, all DoIT groups showed more beneficial changes than CON in (i) muscular strength (+9%–25%, p < 0.001); ii) muscular endurance (+19%–107%, p < 0.001); (iii) flexibility (+19%–24%, p < 0.001); and (iv) static balance (+15%–53%, p < 0.001). DoIT-induced adaptations were largely volume-dependent showing a dose-response relationship between weekly exercise volume and the magnitude of musculoskeletal fitness improvements. These responses were observed even with a limited net exercise time (DoIT-1, 14 min/week). CONCLUSION: These findings suggest that a long-term, low-volume, multicomponent exercise approach incorporating aerobic-based bodyweight drills and resistance-based alternatives into a free-living exercise setting may improve several musculoskeletal fitness markers in a dose-dependent manner in previously inactive, middle-aged individuals with overweight and obesity.