Effect of Threshold Inspiratory Muscle Training on Functional Fitness and Respiratory Muscle Strength Compared to Incentive Spirometry in Children and Adolescents With Obesity: A Randomized Controlled Trial

Abstract

BackgroundTo determine the effect of threshold inspiratory muscle training (IMT) on functional fitness and respiratory muscle strength (RMS) compared to incentive spirometry (IS) in children/adolescents with obesity.MethodsA total of 60 obese children/adolescents aged 8–15 years were randomized into the threshold IMT group (n = 20), the IS group (n = 20), or the control group (n = 20). The IMT group performed 30 inspiratory breaths with the intensity set at 40% of baseline maximal inspiratory pressure (MIP) twice daily for 8 weeks; the IS group performed 30 breaths with sustained maximum inspiration twice daily for 8 weeks; and, the control group was assigned no training device for 8 weeks. Six-min walk test (6-MWT), RMS, and spirometry were compared between baseline and 8 weeks.ResultsSix-MWT distance (528.5 ± 36.2 vs. 561.5 ± 35.2 m, p = 0.002) and MIP (121.2 ± 26.8 vs. 135.3 ± 32.1%Predicted, p = 0.03) were significantly improved after 8 weeks of IMT training. There was no significant difference in any evaluated pulmonary function parameters between baseline and 8 weeks in the IS or control groups; however, 6-MWT distance demonstrated a trend toward significant improvement in the IS group (526.9 ± 59.1 vs.549.0 ± 50.6 m, p = 0.10). No significant difference among groups was found for any variable relative to change from baseline to post-training.ConclusionEight weeks of threshold IMT training significantly improved both inspiratory muscle strength (MIP) and functional fitness (6-MWT) in children/adolescents with obesity. Eight weeks of IS training yielded a trend toward significantly improved functional fitness.

Inspiratory muscle training in patients with obesity: a systematic review and meta-analysis

“…Three studies were conducted in Brazil ( 28–30 ), one in Spain ( 31 ), Australia ( 32 ), Egypt ( 33 ), Taiwan ( 34 ), and Thailand ( 17 ). All studies were published after 2011.…”

“…Sample sizes varied from 14 ( 30 ) to 67 ( 32 ) participants. The studies included 151 (56%) males and 118 (44%) females, with mean ages varying between 11.2 ± 2.6 ( 17 ) and 48 ± 11 ( 32 ) years. One study did not report the male/female distribution ( 30 ).…”

“…The most commonly used load was 30% of maximal inspiratory pressure (MIP) ( 28 , 30 , 31 , 33 ), two studies used 40% ( 17 , 29 ), and two studies used loads of 55% ( 32 , 34 ). Regarding the protocol, five studies were trained by time ( 28–31 , 33 ), and three were trained by repetitions ( 17 , 32 , 34 ). The frequency varied from 3 ( 34 ) to 7 days per week ( 17 , 28–32 ).…”

“…Additionally, regular physical activity and exercise are essential components of obesity treatment, promoting energy expenditure and maintaining muscle mass ( 15 ). Specific exercises that target the respiratory muscles, such as inspiratory muscle training (IMT), have shown potential benefits in improving respiratory function in individuals with obesity ( 16 , 17 ).…”

Effects of an incentive spirometer versus a threshold inspiratory muscle trainer on lung functions in Parkinson’s disease patients: a randomized trial

“…Its primary usage principle is inspiration up to the TLC level, but the inspiration is not directed against resistance. As a result, the TIMT is more successful at increasing respiratory muscle strength than the IS, which results in a smaller increase in functional fitness 58 .…”