Physical exercise in the prevention and treatment of Alzheimer’s disease

Dementia is one of the greatest global challenges for health and social care in the 21st century.Alzheimer’s disease(AD),the most common type of dementia,is by no means an inevitable consequence of growing old.Several lifestyle factors may increase,or reduce,an individual’s risk of developing AD.Much has been written over the ages about the benefits of exercise and physical activity.Among the risk factors associated with AD is a low level of physical activity.The relationship between physical and mental health was established several years ago.In this review,we discuss the role of exercise(aerobic and resistance)training as a therapeutic strategy for the treatment and prevention of AD.Older adults who exercise are more likely to maintain cognition.We address the main protective mechanism on brain function modulated by physical exercise by examining both human and animal studies.We will pay especial attention to the potential role of exercise in the modulation of amyloid b turnover,inflammation,synthesis and release of neurotrophins,and improvements in cerebral blood flow.Promoting changes in lifestyle in presymptomatic and predementia disease stages may have the potential for delaying one-third of dementias worldwide.Multimodal interventions that include the adoption of an active lifestyle should be recommended for older populations.

The COVID-19 pandemic and physical activity

The SARS-CoV-2-caused COVID-19 pandemic has resulted in a devastating threat to human society in terms of health,economy,and lifestyle.Although the virus usually first invades and infects the lung and respiratory track tissue,in extreme cases,almost all major organs in the body are now known to be negatively impacted often leading to severe systemic failure in some people.Unfortunately,there is currently no effective treatment for this disease.Pre-existing pathological conditions or comorbidities such as age are a major reason for premature death and increased morbidity and mortality.The immobilization due to hospitalization and bed rest and the physical inactivity due to sustained quarantine and social distancing can downregulate the ability of organs systems to resist to viral infection and increase the risk of damage to the immune,respiratory,cardiovascular,musculoskeletal systems and the brain.The cellular mechanisms and danger of this“second wave”effect of COVID-19 to the human body,along with the effects of aging,proper nutrition,and regular physical activity,are reviewed in this article.

Reversal of age-associated frailty by controlled physical exercise:The pre-clinical and clinical evidences

Demographic aging is one of the most serious challenges facing our society.Although we live longer,we do not live better because it is considered that approximately 16–20%of our life is spent in late-life morbidity.Older people have the greatest risk of developing frailty increasing the risk of presenting various adverse health events such as low quality of life,disability,hospitalization and even death.Frail men and women over 65 years old have lower muscle quality and muscle mass and higher percentage of body fat than non-frail people of the same age.In this review we will address the main physiological changes in the muscular and nervous system associated to aging.More specifically we will review the changes in muscle mass,quality,and strength relating them with the decrease in capillarization and muscular oxidative capacity as well as with the alterations in protein synthesis in the muscle with aging.The last section of the manuscript will be devoted to the animal models of frailty and the indexes developed to measure frailty in these models.We will finally address the importance of exercise training as an intervention to delay or even reverse frailty.