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Abstract
Degenerative lifestyle-related diseases such as diabetes, cardiovascular disease (CVD), cerebral vascular attack, cancer and cardiopulmonary diseases (CPD) are a specific cluster of physiological disorders that account for the rising global mortality rate. Many forms of CPD can potentially result in death. However, some are preventable with the correct treatment and management of the risk factors. These modifiable risk factors can be addressed through various lifestyle interventions, such as engaging in regular physical activity, body mass/fat loss, reduced tobacco use, stress management, maintaining normal blood pressure and ensuring normal cholesterol levels. Of particular importance is the role that physical activity plays in reducing CPD risk, not only for its direct benefits, but also for its role in indirectly improving other risk factors (i.e. physical activity’s role in reducing overweight/obesity, hypertension, dyslipidemia, etc.). In this regard, it has previously been found that there is a high prevalence of physical inactivity in urban areas (66.5%), due to the technological advances, private transport and automatic machinery, further increasing the prevalence of CPD risk factors and CPD. Problematically, the effects of resistance training on reducing CPD and its related risk factors has only recently gained the attention of health professionals and researchers and has therefore not been researched as in-depth as aerobic training. Due to the various physical and functional adaptations induced by the various modes of resistance training, such as amplified muscular strength and muscle mass, as well as enhanced neuromuscular control and coordination, it is essential to understand which mode of training is most effective in reducing the risk factors associated with CPD. As such, the aim of this study was to compare the effects of eight weeks of muscle endurance and hypertrophy resistance training on cardiopulmonary risk factor reduction in an attempt to minimalise the ever-increasing mortality and morbidity rates associated with CPD. 42 sedentary males were divided into two exercise groups hypertrophy training group (n=15) and a muscle endurance training group (n=13) as well as a non-exercising control group (n=14). The two exercise groups completed their respective one-hour training sessions held three days a week every Monday, Wednesday and Friday for eight weeks, whilst the non-exercising control group continued with their daily routine. The following evaluations were completed during both pre- and post-tests: smoking recall, dietary evaluation, alcohol recall, psychological evaluation, cardiovascular evaluation, haematological evaluation, anthropometric evaluation, resting and basal metabolic rate evaluation, pulmonary function evaluation, abdominal and chest wall excursion evaluation, cardiorespiratory fitness evaluation and muscular strength evaluation. The eight - week hypertrophy resistance training (HT) produced 1 4 significant (p ≤ 0.05) results in the measured psychological measures (i.e. QOL (p=0.018)), cardiovascular measures (i.e. RMAP (p=0.024)), haematological measures (i.e., TC: HDL - C (p=0.009), HDL - C: LDL - C (p=0.008)), anthropometric measures (i.e. HC (p=0.045), body density (p=0.002), LBM (p=0.001), PBF (p=0.000), FM (p=0.006), Ʃ SKF (p=0.002) ) , pulmonary function measures (i.e. PIF (p=0.009)), abdominal and chest wall excursion measures (i.e. maximum lung inhalation (p= 0.000) ) and muscular strength and endurance measures (i.e. leg press 1 - RM (p=0.000), chest press 1 - RM (p=0.000) and one - minute crunches (p=0.000) ) . In turn, the eight weeks of muscle endurance resistance training (MET) programme elicited 2 0 significant cha nges in smoking measures (i.e. units smoked per day (p=0.037), cardiovascular measures (i.e. RSBP (p=0.002), RDBP (p=0.006), RMAP (p=0.000), RPP (p=0.010) and Max HR (p=0.001) ), haematological measures (i.e. TC (p=0.010), TG (p=0.010), LDL - C (p=0.007), HDL - C: LDL - C (p=0.018) and n - HDL - C (p=0.010)), anthropometric measures (i.e. body density (p=0.000), LBM (p=0.004), PBF (p=0.000), FM (p=0.000) and Ʃ SKF (p=0.000)), cardiorespiratory fitness ( p=0.001) and muscular strength and endurance measures (i.e. , leg pr ess 1 - RM (p=0.030), chest press 1 - RM (p=0.001) and one - minute crunches (p=0.000) ) . Interestingly, both the MET and HT protocols resulted in a deleterious decrease in HDL - C (HDL - C (p=0.027 and p=0.026, respectively). T he non - exercising control group produce d no significant changes from pre - to post - test in any of the measured parameters . These findings demonstrate that depending on prevailing risk factor(s) that an individual exhibits, a specific type of resistance training should be implemented. In this reg ard, while the MET improves more parameters, it is important to note that HT was more effective at improving anthropometric measures and is the only mode that improved QOL, pulmonary function abdominal and chest wall excursion measures. In turn, the MET wa s more effective at improving cardiovascular measures and was the only mode to improve cardiorespiratory fitness.