Body Composition and Inflammatory Cytokine Responses to a Pilot Intervention of Resistance Training Combined with a Dietary ‘Bulk and Cut’ Program in Untrained Men

Abstract

This study aimed to pilot a body-building program consisting of resistance training combined with a dietary bulk-and-cut protocol in middle-aged males. To this end, five untrained males with obesity (34.0 ± 3.5 years) participated in a 24-week resistance training intervention combined with a dietary protocol including 12-week cycles of bulking and cutting, respectively. To confirm the feasibility of this pilot intervention, compliance to the 24-week training intervention and adherence to each 12-week dietary cycle were calculated. Venous blood samples, and measurements of body composition (BodPod), muscle strength, and VO2max (cycle ergometer) were collected three times; at baseline (week 0) and following the bulking (week 12) and cutting (week 24) cycles. Circulating inflammatory cytokines, including tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10) were analysed in serum. Compliance with the 24-week training was 96.7 4.3 % and adherence to the bulking and cutting cycles was 93.75.1 % and 94.53.0 %, respectively. Results showed improvements in body composition with an increase in fat-free mass, and a decrease in body fat percentage over the 24-week intervention (+4% and -8%, respectively, p<0.05). Muscle strength increased over time for all exercises with the largest increase in the deadlift (+56%, p<0.001) and the squat (+93%, p<0.001). IL-6 decreased from post-bulking to post-cutting (-26%, p<0.05) while IL-10 and TNF-α decreased from baseline to post-cutting (-19% and -9%, respectively, p<0.05). These preliminary results suggest that resistance training combined with cycles of dietary bulking and cutting is feasible to implement and can lead to improvements in body composition and inflammation status in untrained adult males.