Just today (Jan 2) I finished my 2nd run for this new year! So started with good physical activity. Also some weeks ago, I did my registration for the coming Rotterdam marathon! Physical activity is part of a healthy lifestyle and there is a co-dependence between mental and physical health. But is running a marathon a healthy physical activity? The exact definition of healthy activity remains complex and is possibly different between persons. Perhaps also slightly different btween individuals are the benefits like the inverse relation between physical activity and depression. In this respect, at the end of last year an interesting study was published in which the possible relationship was analyzed between moderate to vigorous physical activity (MVPA) and depression and physical function in midlife https://bit.ly/3VzOStn. The authors studied two UK birth cohorts born within one week in 1958 (n = 7278) and 1970 (n = 6097) with data on depression (ages 33/34; Malaise Inventory), MVPA (age 42; self-reported) and PF (Short Form-36 subscale). Covariates included sex, childhood and adulthood social class, maternal mental health, childhood mood, alcohol consumption, smoking habits, sleep, marital status, BMI and long-standing illness/disability. Logistic regression models examined associations between depression, MVPA and PF. Consistent evidence was found that depression was linked to lower MVPA participation and lower physical function in midlife. Although less frequent MVPA was also linked to worse physical function, there was only minor evidence that MVPA mediated the relationship between depression and PF. There is in this study evidence to consider moderate and frequent physical activity a mild antidepressant. But still how about the amount of physical activity. Another recent study https://bit.ly/3VNuQMo reviews all the effects described in literature of sedentary behavior on the cellular hallmarks of aging using two models of extreme sedentary behavior that are bed rest and spaceflight studies. The described cellular efects are impressive but mainly based on skeletal biopsies showing loss of muscle mass and chronic inflammation. So the one extreme is bed rest, the other probably a marathon everyday: https://nos.nl/l/2458420 . For me it will be somewhere in between this year!