Twelve-Week Exercise Intervention for Improving Insulin Sensitivity and Body Fat Percentage in Men with Overweight and Obesity
Article Sidebar
Main Article Content
Abstract
This study examined whether a supervised twelve-week combined exercise program could improve insulin sensitivity and reduce body fat percentage in sedentary men with overweight and obesity. Fifty-six men aged 33–58 years with body mass index between 27.4 and 38.6 kg·m−2 completed a randomized controlled trial and were allocated to either a supervised exercise group (n = 28) or a usual-care control group (n = 28). The intervention combined moderate-intensity aerobic exercise and progressive resistance training performed four times per week. Primary outcomes were homeostatic model assessment of insulin resistance (HOMA-IR) and body fat percentage. Secondary outcomes included fasting glucose, fasting insulin, waist circumference, body mass, fat-free mass, and estimated VO2peak. Baseline comparability was assessed with independent-samples t tests. Intervention effects were evaluated with baseline-adjusted analysis of covariance supported by paired-samples t tests for within-group change and Pearson correlation for the attendance-response analysis. Results: Baseline values did not differ between groups (all p > 0.80). After twelve weeks, HOMA-IR decreased from 4.49 ± 0.83 to 3.09 ± 0.83 in the exercise group and from 4.54 ± 1.00 to 4.42 ± 1.05 in the control group. Body fat percentage decreased from 32.77% ± 3.91% to 29.83% ± 4.15% in the exercise group, whereas only a trivial change was observed in the control group. Significant adjusted between-group effects were found for HOMA-IR, body fat percentage, waist circumference, body mass, fasting glucose, fasting insulin, estimated VO2peak, and fat-free mass (all p < 0.001 except fat-free mass). Session attendance was positively associated with the magnitude of HOMA-IR improvement (r = 0.53, p = 0.004). A twelve-week combined exercise intervention produced clinically meaningful improvements in insulin sensitivity, adiposity, and fitness in men with overweight and obesity. The findings support structured exercise as a practical non-pharmacological strategy for early metabolic-risk reduction.
Article Details
Issue
Section
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
How to Cite
References
1. W. J. Kraemer and N. A. Ratamess, “Fundamentals of resistance training: progression and exercise prescription,” Med. Sci. Sports Exerc., vol. 36, no. 4, pp. 674–688, 2004, doi: 10.1249/01.MSS.0000121945.36635.61. DOI: https://doi.org/10.1249/01.MSS.0000121945.36635.61
2. C. E. Garber et al., “Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for prescribing exercise,” Med. Sci. Sports Exerc., vol. 43, no. 7, pp. 1334–1359, 2011, doi: 10.1249/MSS.0b013e318213fefb. DOI: https://doi.org/10.1249/MSS.0b013e318213fefb
3. S. N. Blair et al., “Physical fitness and all-cause mortality: A prospective study of healthy men and women,” JAMA, vol. 262, no. 17, pp. 2395–2401, 1989, doi: 10.1001/jama.1989.03430170057028. DOI: https://doi.org/10.1001/jama.1989.03430170057028
4. R. Ross et al., “Importance of assessing cardiorespiratory fitness in clinical practice: A case for fitness as a clinical vital sign,” Circulation, vol. 134, no. 24, pp. e653–e699, 2016, doi: 10.1161/CIR.0000000000000461. DOI: https://doi.org/10.1161/CIR.0000000000000461
5. S. R. Colberg et al., “Exercise and type 2 diabetes: the American College of Sports Medicine and the American Diabetes Association: joint position statement,” Diabetes Care, vol. 33, no. 12, pp. e147–e167, 2010, doi: 10.2337/dc10-9990. DOI: https://doi.org/10.2337/dc10-9990
6. D. E. Kelley and B. H. Goodpaster, “Effects of exercise on glucose homeostasis in type 2 diabetes mellitus,” Med. Sci. Sports Exerc., vol. 33, no. 6 Suppl., pp. S495–S501, 2001, doi: 10.1097/00005768-200106001-00020. DOI: https://doi.org/10.1097/00005768-200106001-00020
7. R. Ross and I. Janssen, “Physical activity, total and regional obesity: dose-response considerations,” Med. Sci. Sports Exerc., vol. 33, no. 6 Suppl., pp. S521–S527, 2001, doi: 10.1097/00005768-200106001-00023. DOI: https://doi.org/10.1097/00005768-200106001-00023
8. D. H. Slentz et al., “Effects of the amount of exercise on body weight, body composition, and measures of central obesity,” Arch. Intern. Med., vol. 164, no. 1, pp. 31–39, 2004, doi: 10.1001/archinte.164.1.31. DOI: https://doi.org/10.1001/archinte.164.1.31
9. T. S. Church et al., “Effects of aerobic and resistance training on hemoglobin A1c levels in patients with type 2 diabetes: a randomized controlled trial,” JAMA, vol. 304, no. 20, pp. 2253–2262, 2010, doi: 10.1001/jama.2010.1710. DOI: https://doi.org/10.1001/jama.2010.1710
10. M. J. Sigal et al., “Effects of aerobic training, resistance training, or both on glycemic control in type 2 diabetes,” Ann. Intern. Med., vol. 147, no. 6, pp. 357–369, 2007, doi: 10.7326/0003-4819-147-6-200709180-00005. DOI: https://doi.org/10.7326/0003-4819-147-6-200709180-00005
11. E. Bacchi et al., “Metabolic effects of aerobic training and resistance training in type 2 diabetic subjects: a randomized controlled trial (the RAED2 study),” Diabetes Care, vol. 35, no. 4, pp. 676–682, 2012, doi: 10.2337/dc11-1655. DOI: https://doi.org/10.2337/dc11-1655
12. T. Y. Houmard et al., “Effect of the volume and intensity of exercise training on insulin sensitivity,” J. Appl. Physiol., vol. 96, no. 1, pp. 101–106, 2004, doi: 10.1152/japplphysiol.00707.2003. DOI: https://doi.org/10.1152/japplphysiol.00707.2003
13. J. A. Hawley, M. Hargreaves, M. J. Joyner, and J. R. Zierath, “Integrative biology of exercise,” Cell, vol. 159, no. 4, pp. 738–749, 2014, doi: 10.1016/j.cell.2014.10.029. DOI: https://doi.org/10.1016/j.cell.2014.10.029
14. S. R. Bird and J. A. Hawley, “Update on the effects of physical activity on insulin sensitivity in humans,” BMJ Open Sport Exerc. Med., vol. 2, no. 1, Art. no. e000143, 2017, doi: 10.1136/bmjsem-2016-000143. DOI: https://doi.org/10.1136/bmjsem-2016-000143
15. F. M. Finucane et al., “The effects of aerobic exercise on metabolic risk, insulin sensitivity and intrahepatic lipid in healthy older people from the Hertfordshire Cohort Study: a randomized controlled trial,” Diabetologia, vol. 53, no. 4, pp. 624–631, 2010, doi: 10.1007/s00125-009-1641z. DOI: https://doi.org/10.1007/s00125-009-1641-z
16. J. M. Oppert et al., “Exercise training in the management of overweight and obesity in adults: synthesis of the evidence and recommendations from the European Association for the Study of Obesity Physical Activity Working Group,” Obes. Rev., vol. 22, Suppl. 4, Art. no. e13273, 2021, doi: 10.1111/obr.13273. DOI: https://doi.org/10.1111/obr.13273
17. H. S. Lee and J. Lee, “Effects of exercise interventions on weight, body mass index, lean body mass and accumulated visceral fat in overweight and obese individuals: A systematic review and meta-analysis of randomized controlled trials,” Int. J. Environ. Res. Public Health, vol. 18, no. 5, Art. no. 2635, 2021, doi: 10.3390/ijerph18052635. DOI: https://doi.org/10.3390/ijerph18052635
18. S. Amanat et al., “A randomized controlled trial on the effects of 12 weeks of aerobic, resistance, and combined exercises training on the serum levels of nesfatin-1, irisin-1 and HOMA-IR,” Front. Physiol., vol. 11, Art. no. 562895, 2020, doi: 10.3389/fphys.2020.562895. DOI: https://doi.org/10.3389/fphys.2020.562895
19. S. S. Ho et al., “The effect of 12 weeks of aerobic, resistance or combination exercise training on cardiovascular risk factors in the overweight and obese in a randomized trial,” BMC Public Health, vol. 12, Art. no. 704, 2012, doi: 10.1186/1471-2458-12-704. DOI: https://doi.org/10.1186/1471-2458-12-704
20. H. AbouAssi et al., “The effects of aerobic, resistance, and combination training on insulin sensitivity and secretion in overweight adults from STRRIDE AT/RT: a randomized trial,” J. Appl. Physiol., vol. 118, no. 12, pp. 1474–1482, 2015, doi: 10.1152/japplphysiol.00509.2014. DOI: https://doi.org/10.1152/japplphysiol.00509.2014
21. W. Park et al., “Effects of resistance- and aerobic-exercise for 12 weeks on body composition, hemodynamic function, and exercise performance in Korean adults with obesity,” Int. J. Environ. Res. Public Health, vol. 17, no. 19, Art. no. 7233, 2020, doi: 10.3390/ijerph17197233. DOI: https://doi.org/10.3390/ijerph17197233
22. S. W. Kim et al., “Twelve weeks of combined resistance and aerobic exercise improves cardiometabolic biomarkers and enhances red blood cell hemorheological function in obese older men: A randomized controlled trial,” Int. J. Environ. Res. Public Health, vol. 16, no. 24, Art. no. 5020, 2019, doi: 10.3390/ijerph16245020. DOI: https://doi.org/10.3390/ijerph16245020
23. K. C. Shih and C. F. Kwok, “Exercise reduces body fat and improves insulin sensitivity and pancreatic beta-cell function in overweight and obese male Taiwanese adolescents,” BMC Pediatr., vol. 18, Art. no. 80, 2018, doi: 10.1186/s12887-018-1025-y. DOI: https://doi.org/10.1186/s12887-018-1025-y
24. B. Strasser, “Physical activity in obesity and metabolic syndrome,” Ann. N. Y. Acad. Sci., vol. 1281, no. 1, pp. 141–159, 2013, doi: 10.1111/j.1749-6632.2012.06785.x. DOI: https://doi.org/10.1111/j.1749-6632.2012.06785.x
25. L. A. Bateman et al., “Comparison of aerobic versus resistance exercise training effects on metabolic syndrome (from the Studies of a Targeted Risk Reduction Intervention Through Defined Exercise–STRRIDE-AT/RT),” Am. J. Cardiol., vol. 108, no. 6, pp. 838–844, 2011, doi: 10.1016/j.amjcard.2011.04.037. DOI: https://doi.org/10.1016/j.amjcard.2011.04.037