Trent J Herda1, Eric D Ryan2,3, Martin Kohlmeier4,5, Michael A Trevino6, Gena R Gerstner2,3, Erica J Roelofs7. 1. Neuromechanics Laboratory, University of Kansas, Lawrence, Kansas. 2. Neuromuscular Research Laboratory, Department of Exercise Science and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. 3. Human Movement Science Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. 4. Department of Nutrition, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. 5. Nutrigenetics Laboratory, University of North Carolina at Chapel Hill, Kannapolis, North Carolina. 6. Biodynamics and Human Performance Center, Department of Health Sciences, Georgia Southern University, Savannah, GA. 7. Department of Nutrition, Health and Human Performance, Meredith College, Raleigh, North Carolina.
Abstract
Neuromuscular function in young overweight/obese (OF) children is not well described. AIM: This study examined isometric and isokinetic leg extensor strength, muscle size (mCSA) and tissue composition as measured via echo intensity (mEI), and motor unit (MU) firing rates in normal weight (NW) and OF children aged 7-10 years. METHODS: Fourteen NW (eight girls and six boys, BMI: 15.8 ± 1.4 kg/m2 ) and 15 OF (10 girls and five boys, BMI: 20.8 ± 2.3 kg/m2 ) children volunteered to perform this study. Percentage body fat (%BF) was measured, and mCSA, mEI, and subcutaneous fat (sFAT) of the vastus lateralis (VL) was assessed. MU mean firing rates (MFRs) in relation to recruitment threshold (RT) of the VL were assessed during submaximal isometric contractions. Maximal isokinetic contractions were performed at 1.05 and 4.20 rad/s. The 95% confidence intervals (CI) from the statistical tests are presented. RESULTS: The OF children had greater %BF (95% CI = -15.1 to -7.2), mCSA (95% CI = -4.1 to -1.2), mEI (95% CI = -22.3 to -5.9), and sFAT (95% CI = -0.5 to -0.1), greater rate of strength loss with increasing isokinetic velocities (95% CI = 0.4 to 5.4), and a smaller range of MFRs (95% CI = 0.007 to 7.136) at the steady torque than the NW children. CONCLUSIONS: The OF children had poorer muscle tissue composition, greater velocity-related impairments in muscle strength, and a smaller range of MFRs at the targeted torque that may suggest altered MU recruitment strategies. Interventions in OF children should include exercises and recruit higher-threshold MUs, such as high-intensity resistance exercises.
Neuromuscular function in young overweight/obese (OF) children is not well described. AIM: This study examined isometric and isokinetic leg extensor strength, muscle size (mCSA) and tissue composition as measured via echo intensity (mEI), and motor unit (MU) firing rates in normal weight (NW) and OF children aged 7-10 years. METHODS: Fourteen NW (eight girls and six boys, BMI: 15.8 ± 1.4 kg/m2 ) and 15 OF (10 girls and five boys, BMI: 20.8 ± 2.3 kg/m2 ) children volunteered to perform this study. Percentage body fat (%BF) was measured, and mCSA, mEI, and subcutaneous fat (sFAT) of the vastus lateralis (VL) was assessed. MU mean firing rates (MFRs) in relation to recruitment threshold (RT) of the VL were assessed during submaximal isometric contractions. Maximal isokinetic contractions were performed at 1.05 and 4.20 rad/s. The 95% confidence intervals (CI) from the statistical tests are presented. RESULTS: The OF children had greater %BF (95% CI = -15.1 to -7.2), mCSA (95% CI = -4.1 to -1.2), mEI (95% CI = -22.3 to -5.9), and sFAT (95% CI = -0.5 to -0.1), greater rate of strength loss with increasing isokinetic velocities (95% CI = 0.4 to 5.4), and a smaller range of MFRs (95% CI = 0.007 to 7.136) at the steady torque than the NW children. CONCLUSIONS: The OF children had poorer muscle tissue composition, greater velocity-related impairments in muscle strength, and a smaller range of MFRs at the targeted torque that may suggest altered MU recruitment strategies. Interventions in OF children should include exercises and recruit higher-threshold MUs, such as high-intensity resistance exercises.
Authors: Gabrielle A Donlevy; Sarah P Garnett; Kayla M D Cornett; Marnee J McKay; Jennifer N Baldwin; Rosemary R Shy; Sabrina W Yum; Timothy Estilow; Isabella Moroni; Maria Foscan; Emanuela Pagliano; Davide Pareyson; Matilde Laura; Trupti Bhandari; Francesco Muntoni; Mary M Reilly; Richard S Finkel; Janet E Sowden; Katy J Eichinger; David N Herrmann; Michael E Shy; Joshua Burns; Manoj P Menezes Journal: Neurology Date: 2021-09-07 Impact factor: 9.910
Authors: Cristina Comeras-Chueca; Lorena Villalba-Heredia; Jose Luis Perez-Lasierra; Jorge Marín-Puyalto; Gabriel Lozano-Berges; Ángel Matute-Llorente; Germán Vicente-Rodríguez; Alex Gonzalez-Aguero; José A Casajús Journal: Int J Environ Res Public Health Date: 2022-02-24 Impact factor: 3.390