The Effect of Combined Machine and Body Weight Circuit Training for Women on Muscle Strength and Body Composition

IntroductionHealth-related fitness, built on periodical physical activity and appropriate energy intake, has a preventive impact on health problems arising from hypokinesia (Aidar et al., 2014; Bouchard, Blair, & Haskell, 2006; Corbin & Pangrazi, 1992). A frequently used method to develop or maintain both performance and health-related fitness among the general population is circuit training (CT). CT allows to use a high variety of workout program such as consecutive change of exercises for the upper and lower body, agonist and antagonist muscle groups or complex and isolated exercises (Siff, 2003). Another advantage is the possibility to perform CT as a group exercise, where the trainer has a space for individual interaction with the exerciser (Klee, 2003). CT, with regards to its modality, may stimulate strength endurance, strength, endurance and may compensate muscle imbalances and change body composition (Kerksick et al., 2009; Kraemer, Ratamess, & French, 2002). It was also proved that resistance CT may be an effective training strategy not only for the promotion of strength, but at the same time for cardiovascular adaptations and body composition changes (Alcaraz, Sanchez-Lorente, & Blazevich, 2008; Mayorga-Vega, Viciana, & Cocca, 2013; Sawczyn et al., 2014). On the other hand, the disadvantage of resistance CT is a lack of time to set up individual resistance (when there is no resistance machine) including its progressive increase. The reason is that physical training, strength training included, is generally most effective if the load is individualized and work out parameters are periodically changed toward the training goal (Igor & Vladimir, 2010; Siff, 2003; P. Stastny, Lehnert, Zaatar Zaki, Svoboda, & Xaverova, 2015). Although periodization was proven to be an effective approach in longer training programs with resistance CT (Marx et al., 2001), this requirement might not be necessary in untrained population, where the health aspect of exercise is the priority and adaptability to exercise routine in this population is much lower than in athletes.A plethora of modifications of resistance CT training are used by trainers to match specific needs for women, especially the need for relatively low-intensity exercises without increasing the resistance, but with low rest intervals. If there is no increase of exercise resistance, there should be another loading parameter, which might increase the effectiveness of the workout program such as an antagonistic hydraulic training system, which works in a concentric antagonistic regime. Thus, CT can combine a hydraulic resistance machine with weight bearing exercises, and complex and isolated exercises can be used. This training compromise is applied in women's group exercise as combined antagonist hydraulic resistance circuit training (CAHCT). The effect of CAHCT was previously examined in a fourteen-week intervention, which suggested that only a combination of CAHCT and diet restriction can change body composition effectively (Kerksick et al., 2009). The aim of this study is to find out whether CAHCT applied in women for 12 weeks will change body composition and strength as an important characteristic of health-related fitness.Material & methodsThe research was performed using an intervention study design with a pre-test and post-test. The pre-test was performed three days before the first training session. The participants performed three 40min training sessions per week for three months.ParticipantsThirteen healthy novices (age 36.2 ± 9.9 years, height 168.3 ± 7.8 cm, weight 78.7 ± 13.3 kg) were recruited from a women's fitness club FitCurves in Olomouc. Participant recruitment was done by public announcement. The inclusion criterion was absence of regular strength training for at least 5 months. Only 13 women out of the 45 interested in participation matched the estimated criteria, 9 women finished the study and were included into the analysis. …