Circuit resistance training in sedentary women: body composition and serum cytokine levels.

Exercise can generate alterations in body composition and modulate the immune system. The objective of this study was to verify whether a circuit resistance training (CRT) protocol can increase lean body mass (LM), and reduce fat body mass (FM) and the percent of FM (%FM) of sedentary women, without inducing inflammatory responses, indicated by serum cytokine levels. The initial hypothesis was that CRT would improve body composition, without changing serum cytokine levels. The study consisted of 14 healthy, sedentary women, aged 33-45 years (mean +/- SD, 40.23 +/- 3.98 years), with a normal body mass index. They participated in 3 sessions per week of CRT, which included 2 rounds in 9 stations with 1 set of 8-12 repetition maximum at each station, for 10 weeks. During the 10-week CRT period, participants maintained their pretraining nutritional standard. Body composition was analysed with dual-energy X-ray absorptiometry both pre- and post-training. Blood samples were collected after 96 h of rest pre- and post-training, and 5 min, 24 h, and 48 h after the second and last training sessions to measure serum cytokine levels by flow cytometry. The nutritional standard was accompanied throughout the study period with 24-h dietary recall. Increases in LM (35.937 +/- 4.926 to 39.130 +/- 4.950 kg) and decreases in FM (21.911 +/- 8.150 to 17.824 +/- 4.235 kg) and %FM (37.10 +/- 10.84 to 31.19 +/- 6.06), without concurrent changes in serum cytokine levels, and in the nutritional standard (alpha = 0.05). The proposed CRT improved body composition and did not induce any changes in serum cytokine levels characteristic of the inflammatory response in women.