RESUMO
PURPOSE: Chronic, high-altitude hypoxic exposure increases the risk of high-altitude pulmonary hypertension (PH). Emerging evidence shows maternal exercise may improve offspring resistance to disease throughout life. The purpose of this study is to determine if maternal exercise mitigates chronic hypoxic-induced changes in the offspring indicative of high-altitude pulmonary hypertension development. METHODS: Female adult C57BL/6 J mice were randomly allocated to nonexercise or exercise conditions. Exercise consisted of voluntary running wheel exercise for four weeks during the perinatal period. Three days after birth, the pups remained at low altitude (normoxia) or were exposed to hypobaric hypoxia of 450 mmHg to simulate ~4500 m altitude exposure until 8 weeks of age. The study consisted of 4 groups: Hypoxia + Nonexercise pregnancy, Hypoxia + Exercise, or the respective, normoxia conditions (Normoxia + Nonexercise or Normoxia + Exercise). Offspring body size, motor function, right ventricular systolic pressure (RVSP), and cardiopulmonary morphology were assessed after 8 weeks in normoxia or hypoxia. RESULTS: Both hypoxic groups had smaller body sizes, reduced motor function, increased hematocrit, RVSP, muscularization in medium-sized pulmonary arteries, as well as right ventricular hypertrophy and contractility compared to the normoxic groups ( p < 0.05). CONCLUSIONS: Chronic hypoxia simulating 4500 m attenuated growth, lowered motor function, and elicited PH development. Voluntary maternal exercise did not significantly decrease RVSP in the offspring, which aligned with a lack of effect to attenuate abnormal body size and cardiopulmonary development due to chronic hypoxia. These findings are preliminary in nature and more powered studies through larger group sizes are required to generalize the results to the population.
RESUMO
Older adults (≥ 65 years) are recommended to participate in regular exercise to maintain health in late adulthood. The impact of long-term (20+ years) exercise training that align with the American College of Sports Medicine's (ACSM) recommended guidelines has not been evaluated for older adults. To address this, a systematic review and meta-analyses were performed regarding the effects of long-term exercise training on older adult aerobic capacity, muscular fitness, and body composition that meet the ACSM's recommendation for weekly training volume. Ten studies with individuals that performed cardiorespiratory or resistance exercise met the inclusion criteria for the systematic review. Data from five included studies were analyzed in meta-analyses to determine the relationship between the effects of cardiorespiratory training on fitness and body composition measured in the same subjects. Main findings include higher cardiorespiratory fitness (MD: +11.36 mL/kg/min, 95% CI: 5.63 to 17.09 mL/kg/min, p < 0.01) in older adults who performed long-term cardiorespiratory exercise that was found in conjunction with lower percent body fat (MD: -5.41%, 95% CI: -7.65 to -3.17%, p < 0.01). Higher volume of cardiorespiratory exercise beyond the minimum recommendations did not impact benefits. Additionally, resistance-trained older adults showed greater muscular strength and lower percent body fat with comparable cardiorespiratory fitness to sedentary older adults. These findings primarily highlight a preservation of cardiorespiratory fitness and lower risk of mortality and cardiometabolic disease risk for older adults who participate in long-term cardiorespiratory and exercise that meet the ACSM's recommended weekly training volume.