Effects of Resistance Training on Muscular Adaptations and Inflammatory Markers in Overweight and Obese Men

ABSTRACT Purpose: Obesity may blunt exercise responsiveness to improve muscular adaptations. The effect of resistance training (RT) targeting different body regions on muscle and inflammatory markers is unclear. This study aimed to investigate the impact of upper (upper body exercises), lower (lower body exercises), or combined (upper body + lower body exercises) RT on muscle and inflammatory markers, body composition, and performance in overweight and obese men. Methods: Sixty overweight and obese men (age = 31 ± 4 years) were randomly assigned to one of 4 groups: upper-body RT (UB; n = 15), lower-body RT (LB; n = 15), combined RT (UB + LB; n = 15) or control (C; n = 15). The training protocol consisted of 3 exercise sessions per week for 12 weeks. Blood samples for measuring serum markers (follistatin, myostatin, C-reactive protein [CRP], adiponectin, tumor necrosis factor-α [TNF-α], and irisin) were obtained at baseline and 48 hours after the final training session. Fat mass (FM), body fat percentage (BFP), skeletal muscle mass (SMM), and fat-free mass (FFM) were measured using bioelectrical impedance analysis (Inbody 720). Results: SMM, FFM, UB and LB strength and power, follistatin, follistatin:myostatin ratio, adiponectin, and irisin significantly increased while FM, BFP, myostatin, CRP, and TNF-α significantly reduced from pre- to post-training in all training groups (p < 0.05). Changes in LB muscle power (r = 0.558), both UB (r = 0.518) and LB (r = 0.419) muscle strength, and follistatin (r = 0.545), had moderate positive relationships with ΔSMM, while changes in myostatin (r = -0.585) had a moderate negative relationship with ΔSMM. Also, changes in myostatin (r = 0.825) and CRP (r = 0.715) had a strong positive relationship with ΔFM, while TNF-α (r = 0.467) had a moderate positive relationship with ΔFM. Follistatin (r = -0.789) and adiponectin (r = -0.713) had a strong negative relationship with ΔFM, while irisin (r = -0.426) had a moderate negative relationship with ΔFM. Conclusions: Combined RT elicits the greatest increases in follistatin, follistatin:myostatin ratio, adiponectin, and decreases in myostatin and CRP compared with other training groups in overweight and obese men. However, systemic improvements may be achieved through performing UB or LB RT alone.