Serum myokine levels after linear and flexible non-linear periodized resistance training in overweight sedentary women

Abstract

This study compared the capacity of linear-(LP) and non-linear periodized (NLP) resistance training to improve select myokines and metabolic parameters in overweight sedentary women. An additional purpose was to compare these variables between the overweight and lean women. Fitness- and age-matched overweight women between 28 and 43 years old were randomly allocated to LP (body fat [BF]% = 38.7 ± 2.6, n = 10), NLP (BF% = 39.3 ± 2.4, n = 9) and control (BF% = 39.8 ± 2.6, n = 9) groups. Lean women (BF% = 29.1 ± 2.3, n = 16) matched for age and fitness were also included for baseline comparison. Resistance training programmes (12 weeks, 3 d.wk^-1, 9 exercises, 60-90% of 1-repetition maximum [1RM]) were performed with different periodization schemes. Glucose, insulin, interleukin (IL)-7, IL-15, and insulin-like growth factor (IGF)-1 levels were measured at baseline and after training. Overweight subjects had significantly lower IL-15, IGF-1 and higher insulin, glucose, and insulin resistance (homeostasis model assessment, HOMA-IR) than lean subjects at baseline (all, P < .05). IL-15 and VO₂max increased significantly after NLP compared with CON, which was accompanied by a significant decrease in HOMA-IR (all, P < .03). Muscular endurance improved significantly in both models after training compared to CON (all, P < .01), but it increased more in NLP than in LP (P = .01). Both training protocols were equally effective at reducing BF% and increasing IGF-1, IL-7, muscle mass and bench press 1RM (P < .01). It appears that LP and NLP are both effective strategies for improving health markers in overweight women, but LP is not as effective as NLP to improve IL-15, HOMA-IR and aerobic capacity.HighlightsOverweight women had a significantly lower IL-15 and IGF-1 compared to lean encounters, but no significant difference was noted for maximal strength, aerobic capacity, muscle mass, IL-7 and neutrophil/lymphocyte ratio.Twelve weeks of either linear or flexible non-linear periodized resistance training resulted in reduction in BF% and neutrophil/lymphocyte ratio, and increased IGF-1, IL-7, muscle mass and bench press 1RM, with no difference between the two training protocols.Linear protocol is not as effective as non-linear protocol to improve IL-15, HOMA-IR and aerobic capacity.

Keywords: Exercise training; Metabolic health; Periodization; insulin resistance; interleukin-15; maximal oxygen consumption.