Endurance Training vs. Circuit Resistance Training: Effects on Lipid Profile and Anthropometric/Body Composition Status in Healthy Young Adult Women

Exercise Metabolome: Insights for Health and Performance

Exercise has many benefits for physical and mental well-being. Metabolomics research has allowed scientists to study the impact of exercise on the body by analyzing metabolites released by tissues such as skeletal muscle, bone, and the liver. Endurance training increases mitochondrial content and oxidative enzymes, while resistance training increases muscle fiber and glycolytic enzymes. Acute endurance exercise affects amino acid metabolism, fat metabolism, cellular energy metabolism, and cofactor and vitamin metabolism. Subacute endurance exercise alters amino acid metabolism, lipid metabolism, and nucleotide metabolism. Chronic endurance exercise improves lipid metabolism and changes amino acid metabolism. Acute resistance exercise changes several metabolic pathways, including anaerobic processes and muscular strength. Chronic resistance exercise affects metabolic pathways, resulting in skeletal muscle adaptations. Combined endurance-resistance exercise alters lipid metabolism, carbohydrate metabolism, and amino acid metabolism, increasing anaerobic metabolic capacity and fatigue resistance. Studying exercise-induced metabolites is a growing field, and further research can uncover the underlying metabolic mechanisms and help tailor exercise programs for optimal health and performance.

Response and Adaptation of the Cardiac Autonomic System to Functional High-intensity Interval Training with Respiratory Facemasks: Impacts of the Training Period and Facemask Modality During a COVID-19 Pandemic

Background: Following the SARS-CoV-2 pandemic in 2019, medical face masks were widely recommended for large numbers of people and for long periods of time. The effect of wearing surgical and N95 face masks during long-term high-intensity interval training on the cardiac autonomic system has not been reported. Methods: Eighteen healthy men were randomly divided into three groups (surgical mask, N95 mask, and no mask) and performed high-intensity interval training with (80-90%-heart rate max) intensity three times a week, three repetitions in a session for four weeks. Heart rate variability parameters were evaluated with an electrocardiogram device and Kubius software. The R-R interval was recorded for 5 minutes in a sitting position in the pre-and post-modified Bruce test before and after four weeks of interval training to extract parasympathetic (RMSSD, HF, SD1), sympathetic indices (LF, LF/HF) and RR mean. We used the two-way ANOVA test and the Bonferroni post hoc test. Results: In all groups, four-week functional HIIT exercises increased the resting parasympathetic indices (RMSSD, SD1) compared to baseline levels. This increase was more evident in the N95 mask group than in the surgical mask group. In addition, the five-minute recovery of the cardiac autonomic system after a modified Bruce test following functional HIIT exercise increased parasympathetic tone (RMSSD, HFn.u) in all groups compared to baseline levels. Therefore, a four-week adaptation to HIIT exercises leads to faster recovery of sympathetic indices (LFn.u, LF/HF) in the Nomask group, as compared to the surgical and N95 groups. Despite the above, there was no significant difference in the recovery and resting values of cardiac autonomic system indices between the two types of surgical masks and N95 compared to the control group (No mask). Conclusions: Four weeks of high-intensity interval training using surgical and N95 face masks improved the cardiac autonomic nervous system. This data is important for recommending the use of face masks during physical activity.

Differential Effects of Resistance- and Endurance-Based Exercise Programs on Muscular Fitness, Body Composition, and Cardiovascular Variables in Young Adult Women: Contextualizing the Efficacy of Self-Selected Exercise Modalities

There is an evident lack of research simultaneously investigating endurance training (ET) and resistance training (RT) with regard to their potential influence on fitness and health status in young women. This study aimed to determine the effects of RT and ET three times a week over an eight-week period on anthropometric/body composition indices, blood pressure (BP), and muscular fitness in apparently healthy young women who participated in a self-preferred program. The sample of participants comprised 57 young healthy women (23.9 ± 3.08 years, 165.5 ± 5.8 cm, 66.8 ± 7.2 kg) divided into ET (n = 18), RT (n = 19), and non-exercising (C) (n = 20) groups. The variables consisted of anthropometric/body composition indices (body mass, BMI, body fat, and lean body mass), muscular fitness variables (lower body strength, upper body strength, abdominal strength, dynamometric force, and flexibility), and cardiovascular parameters (resting heart rate and systolic and diastolic BP). A pre- and post-testing design, with factorial analysis of variance for repeated measurements (ANOVA: Group × Measurement), including a consecutive post hoc test, was applied. The ANOVA indicated a similar improvement in body composition (increase in lean body mass and decrease in body fat percentage), resting heart rate, and flexibility in both of the exercise groups, with no significant changes in the C group. RT improved the participants' strength and force capacities to a greater extent than ET. BP showed a trend of improvement in both of the training groups, but without statistically significant pre- to post-changes. Correlation analysis calculated with variables of pre- to post-differences (VDs) indicated poor associations between VDs, indicating relative independence of the obtained effects for the different variables in each training group. Although this investigation comprised apparently healthy young women, numerous positive changes indicated the efficacy of both programs in a relatively short period of time. While the participants in this study self-selected training programs, the evidenced positive effects can be at least partially related to this fact.

Effects of Resistance Circuit-Based Training on Body Composition, Strength and Cardiorespiratory Fitness: A Systematic Review and Meta-Analysis

We assessed the effects of resistance circuit-based training (CT) on strength, cardiorespiratory fitness, and body composition. A systematic review with meta-analysis was conducted in three databases, ending on March, 2020. Meta-analysis and subgroup analysis were used to analyze the effects of pre-post-intervention CT and differences from control groups (CG). Of the 830 studies found, 45 were included in the meta-analysis (58 experimental groups (n = 897) and 34 CG (n = 474)). The CT interventions led to increases in muscle mass (1.9%; p < 0.001) and decreases in fat mass (4.3%; p < 0.001). With regard to cardiorespiratory fitness, CT had a favorable effect on VO2max (6.3%; p < 0.001), maximum aerobic speed or power (0.3%; p = 0.04), and aerobic performance (2.6%; p = 0.006) after training. Concerning strength outcome, the CT increased the strength of the upper and lower extremities. Only the magnitude of strength performance appears to be influenced by the training (number of sessions and frequency) and the training status. Moreover, low and moderate intensities and short rest time between exercise increase the magnitude of change in fat mass loss. Therefore, CT has been shown to be an effective method for improving body composition, cardiorespiratory fitness, and strength of the lower and upper limbs.

Indices of Cardiovascular Health, Body Composition and Aerobic Endurance in Young Women; Differential Effects of Two Endurance-Based Training Modalities

Endurance training (ET) has multiple beneficial effects on cardiovascular health (CVH), but there is an evident lack of knowledge on differential effects of various types of ET on indices of CVH in women. The aim of this study was to analyse the effectiveness of two different types of ET on changes in indicators of CVH in apparently healthy adult women. The sample included 58 women (24 ± 3 years; height: 165 ± 6 cm, mass: 66.7 ± 7.2 kg, BMI: 24.3 ± 2.5 kg/m², at baseline) divided into one control non-exercising group (n = 19), and two exercising experimental groups (EE). The first EE participated in choreographed aerobic-endurance training (CAT; n = 19), while the second participated in treadmill-based endurance exercise (TEE; n = 20) during the experimental protocol (8 weeks, 24 training sessions). The testing included pre- and post-exercise protocols and measures of anthropometric/body composition indices, lipid panel, and endurance capacity. Two-way analysis of variance for repeated measurements with consecutive post hoc analysis was applied to the “group” and “measurement” variables. The main significant ANOVA effects found for measurement, and “Group x Measurement” interaction (p < 0.05) were found for all variables but body height. The EE induced positive changes in lipid panel variables, anthropometric/body-build status, and endurance capacity. However, TEE improved endurance capacity to a greater extent than CAT. The results suggest that that the optimal exercise intensity and self-chosen type of physical-activity may result in positive effects on indices of CVH, even in women of young age and good health status.