ECSS Paris 2023: CP-MH06
INTRODUCTION: Heat therapy can replicate some of the long-term adaptations of exercise training which underpin improvements in cardiovascular health [1]. It is estimated that 25% of adults do not meet the minimum recommended physical activity guidelines [2]. However, many take part in irregular, less intense and infrequent bouts of physical activity within their weekly routines. The use of hot water immersion after exercise has the potential to augment the cardiovascular health benefits from smaller amounts of exercise. Therefore, this study investigated whether post exercise hot water immersion (EX+HWI) can improve cardiovascular health by a greater extent than post exercise thermoneutral water immersion (EX+TNWI). METHODS: After ethical approval, twenty-four physically inactive middle-aged adults (14 females and 10 males; age: 58 ± 5 years; weight: 78 ± 12 kg; height: 1.67 ± 0.08 m; V̇O2 peak: 18 ± 3 ml/kg/min-1) were randomised to either 8-weeks of EX+HWI (n=12) or EX+TNWI (n=12). Volunteers visited the laboratory 2-4 times per week to take part in exercise plus immersion sessions (total 24 sessions). The exercise component was for a duration of 30 minutes and consisted of 10 minutes cycling, rowing and brisk walking at 65%-75% of heart rate maximum. Water immersion was for 30 minutes at a temperature of either 40 °C or 34 °C. A range of cardiovascular health parameters were measured pre, midway and post intervention, including cardiorespiratory fitness, blood pressure, brachial artery endothelial function, carotid to femoral arterial stiffness and serum cardiometabolic/inflammatory biomarkers. RESULTS: A time × condition interaction was detected for mean arterial pressure (P=0.039) and diastolic blood pressure (P=0.044). EX+HWI resulted in a greater reduction in mean arterial pressure and diastolic blood pressure at midway (MAP: P<0.001, mean difference= 5 mmHg and DBP: P=0.001, mean difference=5 mmHg) and post (MAP: P=0.011, mean difference= 4 mmHg and DBP: P=0.007, mean difference=4 mmHg) intervention in comparison to EX+TNWI. Furthermore, a main effect of condition was apparent for systolic blood pressure (P=0.003, mean difference=4 mmHg) and central arterial stiffness (P=0.048, mean difference=2.08 m/s). There were no differences between conditions for cardiorespiratory fitness, brachial artery endothelial function and serum cardiometabolic/inflammatory biomarkers (P>0.05). CONCLUSION: Eight weeks of post exercise hot water immersion improved vascular health through reducing blood pressure and central artery stiffness to a greater extent than exercise followed by thermoneutral water immersion in physically inactive middle-aged adults.
Read CV Charles StewardECSS Paris 2023: CP-MH06
INTRODUCTION: The use of anabolic steroids (AS) due to their ergogenic effects has increased for professional and non-professional athletes in the last decades. In turn, among non-professional resistance training practitioners, the main motivation for AS use is related to aesthetics, being consumed independently of medical prescription. Although it has anabolic effects, research in the field indicates that non-therapeutic AS use may lead to cardiovascular damage. However, little is known about their effects on cardiac contractility, especially when combined with resistance training. In this sense, this study aimed to investigate the effects of nandrolone decanoate treatment, combined with resistance training, on hemodynamic parameters, cardiac morphology, and functionality, focusing on coronary bed reactivity and cardiac contractility, both evaluated in isolated hearts. METHODS: Male Wistar rats (N=64), aged 18 weeks, were divided into two groups (N=32): control group treated with vehicle and nandrolone decanoate-treated group. Half of each group (N=16) was subjected to resistance training. Resistance training was implemented through climbing stairs with progressively added load, conducted three times a week. The anabolic steroid was administered once a week, with individualized dosage calculation (5 mg/kg), and the same protocol was used for vehicle application (0.2 ml/kg) over 12 weeks. All groups underwent the following experimental procedures: recording blood pressure and heart rate, cardiac morphofunctional evaluation, analysis of coronary bed reactivity to increased flow, and analysis of left ventricular contractility to β-adrenergic agonist administration by the Langendorff Technique. Nandrolone decanoate and resistance training effects were evaluated by one-way ANOVA. When appropriated, post-hoc comparisons were made by the Student Newman Keuls test. Coronary bed reactivity and dose-response curves after dobutamine and salbutamol administration were analyzed by the multivariate repetitive measures model and post-hoc comparisons when appropriate. Differences were considered significant when p<0.05. RESULTS: Groups treated with nandrolone decanoate showed reduced cardiac contractility, coronary perfusion pressure, maximum and minimum dP/dT, and lower left ventricular systolic pressure in response to dobutamine and salbutamol administration compared to vehicle groups. Morphologically, nandrolone decanoate increased the left ventricles end-diastolic and end-systolic diameter, with increased left ventricular mass and reduced fractional shortening compared to vehicle groups. The nandrolone decanoate effects on these parameters were suppressed when combined with resistance training. CONCLUSION: In addition to inducing changes in cardiac structure, nandrolone decanoate reduced left ventricular contractile responses to flow increase and b-agonist administration. In turn, when combined with resistance training, these effects were suppressed.
Read CV Lucas DalvitECSS Paris 2023: CP-MH06
INTRODUCTION: This study aims to investigates the adaptive changes in cardiovascular endurance among adolescents living at 3500 meters high altitude who have migrated to low altitude areas, and explore the impact of exercise volume on their cardiovascular endurance. METHODS: The sample consists of 188 adolescents (77 boys and 111 girls) from Tibet Middle School in Beijing, China. Before their first year of high school, they all lived in Lhasa, Tibet, a place with an altitude of more than 3500 meters. In 2019, the baseline test was conducted in their first year of high school, age=15.38 ± 0.71 years, BMI=21.9 ± 3.1kg/m2. The test data was collected every September and tracked from the first year of high school to the third year. (1) In baseline test, the test indicators included height, weight, age, BMI, laps and predicted VO2max of Pacer. (2) Through a 3-year longitudinal observation, to explore the changes in Laps and VO2max during the first to third year of high school for adolescents living in high-altitude areas who migrate to low altitudes. (3) Based on the overall tracking survey, the study subjects were randomly divided into two subgroups in their first year of high school: Group A (40 boys and 78 girls, with three regular physical education classes per week) and Group B (37 boys and 33girls, with three regular physical education extracurricular activities per week and three HIIT specific training sessions per week for two hours). The study observed the temporal changes in Laps and VO2max indicators among adolescents who migrated to low altitudes at different levels of exercise. RESULTS: (1) When high altitude students migrate to low altitudes for the first month, Laps of boys is greater than female (boys 62.55±15.45 VS girls 31.10±8.72, p<0.01), and VO2max of boys is also greater than female (boys 47.02 ± 4.39 ml/kg﹒min VS girls 38.39 ± 3.00 ml/kg﹒min, p<0.01). (2) During the first to third year of high school, the Laps of boys and girls showed an upward trend with significant differences (p <0.05); VO2max showed an upward trend among boys (p <0.05), while girls showed a fluctuating downward trend (p <0.05). (3) The Laps and VO2max in Group B were higher than those in Group A students (p <0.05) during the three years in high school. CONCLUSION: After migrating to low altitude areas, the aerobic exercise ability of both boys and girls were improved. The cardiovascular endurance of boys has been significantly improved, but the cardiovascular endurance of girls has shown a downward trend. At the same time, adding HIIT exercises outside of regular physical education may help improve aerobic exercise and cardiovascular endurance for young people living in high-altitude areas who migrate to low altitude areas.
Read CV FAN CHAOQUNECSS Paris 2023: CP-MH06