Impact of Intermittent Fasting Combined With High-Intensity Interval Training on Body Composition, Metabolic Biomarkers, and Physical Fitness in Women With Obesity.

Background: Intermittent fasting (IF) is a dietary approach that is widely popular due to its effects on weight and body fat loss, but it does not appear to ensure muscle mass preservation. Incorporating high-intensity interval training (HIIT) into an individual's routine could be an attractive and viable therapeutic option for improving body composition, lifestyle and health promotion. Problematizing the emerging situation of fighting obesity, led us to clarify gaps about IF and hypothesize that IF and HIIT in conjunction may protect against muscle mass decline without impairing nitrogen balance (NB), in addition to improving the physical fitness of women with obesity. Objectives: To evaluate the effects of IF alone and combined with HIIT on body composition, NB and strength and physical fitness in women with obesity. Methods: Thirty-six women (BMI 34.0 ± 3.2; 32.2 ± 4.4 years) participated and were randomly distributed into three groups: (1) Intermittent fasting combined with exercise group (IF + EX); (2) Exercise group (EX); and (3) Intermittent fasting group (IF). The interventions took place over 8 weeks and all evaluations were performed pre and post-intervention. The HIIT circuit was performed 3x/week, for 25 mins/session, at 70-85% of the maximum heart rate. The intermittent fasting protocol was a 5:2 diet with two meals within 6 h on fasting days, being 25% of total energy intake, plus 18 h of complete fasting. The protocol was performed 2x/week and 5 days of ad libitum ingestion. Resting metabolic rate (RMR) was measured by indirect calorimetry, body composition by BodPod®, NB from urinary nitrogen, food consumption by food records and physical and strength performance were measured by physical tests. ANOVA two-way repeated measures mixed model was performed followed by Sidak post hoc (p < 0.05). This project was registered in ClinicalTrials.gov, NCT05237154. Results: There were a reduction in body weight (P = 0.012) and BMI (P = 0.031) only in the IF + EX group. There was body fat loss in the IF + EX group (-4%, P < 0.001) and in the EX group (-2.3%, P = 0.043), an increase in fat-free mass in the IF + EX group (+3.3%, P < 0.001) and also in the EX group (+2%, P = 0.043), without differences between groups and the IF group showed no changes. The NB was equilibrium in all groups. All parameters of aerobic capacity and strength improved. Conclusion: Combining IF with HIIT can promote increments in fat-free mass, NB equilibrium and improve physical fitness and strength.

Effects of the COVID-19 pandemic on the global health of women aged 50 to 70 years.

AIM/BACKGROUND: The most recent pandemic caused by the new coronavirus disease (COVID-19) urged dramatic changes in people's lives. Potentially, the COVID-19 pandemic affects physical and mental health as well as behavioral and social aspects. However, the direct impacts of the COVID-19 pandemic on health-related parameters are not yet known. The present study aimed to evaluate the effect of 16 weeks during the COVID-19 pandemic on health-related parameters of physically inactive women aged 50 to 70 years. METHODS: Thirty-four physically inactive women participated in the study. We performed tests to evaluate aerobic capacity and muscle strength, anthropometric measurements, blood pressure (BP), blood parameters, diet, and physical activity levels. All evaluations were carried out before and 16 weeks after the initial phase of the COVID-19 pandemic in Brazil (i.e., from March to July 2020). RESULTS: Systolic BP (p < .0001; effect size (ES) = 0.62), diastolic BP (p < .0001; ES = 0.71), grip strength of the right (p < .05; ES = 0.43) and left hand (p < .05; ES = 0.49), performance in six-minute walk test (p < .05; ES = 0.46), free time physical activity levels (p < .05; ES = 0.40), domestic physical activity levels (p < .05; ES = 0.39), platelet count (p < .0001; ES = 0.48), and mean corpuscular hemoglobin concentration (p < .0001; ES = 1.14) reduced in comparison to the period before the pandemic. In contrast, glycated hemoglobin levels (p < .0001; ES = 0.77), triglycerides (p < .05; ES = 0.40), and insulin levels (p < .05; ES = 0.60) increased in comparison to the period before the pandemic. CONCLUSION: The COVID-19 pandemic negatively impacted the general health status of physically inactive women aged 50 to 70, potentially increasing their susceptibility to comorbidities, such as type 2 diabetes and hypertriglyceridemia.