There is a Large Difference in Mortality Rate Between a Sedentary Lifestyle and Daily Physical Activity
Exercise, like all interventions that improve health, has a dose-response curve. As in most such curves, the initial difference between no treatment (a sedentary or near-sedentary lifestyle) and some treatment (moderate physical activity every day) is quite large. Further increments in activity can add increasing benefits, but ever less as activity time increases further. There is an optimal point at which one can be fairly certain of capturing most of the benefits, even given the usual uncertainties in measurement and variation in the response of individuals. For aerobic exercise, and the average human being, the optimal point is probably a greater amount of time than the 30 minutes daily presently recommended.
Regular moderate- to vigorous-intensity physical activity (MVPA) is associated with a lower risk of cardiovascular disease; certain cancers; and premature death. In addition, the amount of time spent sedentary - distinct from physical inactivity - is associated with a higher risk of death and disease. That may be a result, at least in part, from sedentary behavior displacing physical activity.
Most previous studies have explored the potential effect of sedentary time without considering the physical activity it displaces, leaving a gap in the understanding of the issue. To explore further, investigators analyzed self-reported sitting time, light physical activity, and moderate/vigorous physical activity among 92,541 participants in the ACS's Cancer Prevention Study II Nutrition Cohort.
The analysis reviewed sedentary time and activity levels over 14 years. It found among those who were the least active at baseline (less than 17 minutes/day moderate to vigorous physical activity), replacing 30 minutes/day of sitting with light physical activity was associated with a 14% reduced risk of death, while replacement with moderate to vigorous physical activity was associated with a 45% reduced risk of death.
The investigators found similar but smaller associations among moderately active participants: replacing a half hour of sedentary time with light physical activity was associated with a 6% reduction in mortality among those who were moderately active; replacing 30 minutes of sitting time with moderate to vigorous physical activity was associated with a 17% mortality reduction in this group. However, for the most active (more than 38 minutes/day of MVPA), substitution of sitting time with light physical activity or MVPA was not associated with a reduction in mortality risk.
Link: https://www.eurekalert.org/pub_releases/2019-03/acs-rst032519.php
I'll admit to being vain enough that pretty much everything over 30 minutes a day (3 days intense elliptical, 1 day resistance) that I do is about looking great, and based upon how motivated I am any given day. These studies are not long enough to see the effects of hip replacements and conditions created by other wear on the body by the very intense and high duration trainers.
Osteoporosis is not because of "wear"; on the contrary not using your bones in a major risk factor for it and hipfractures and exercise reduces your risk. Your body need pulsatile dose of stressors in order to grow and maintain however anything can be overdone and you easily push your body outside homeostasis by overtraining/exercising (usually you'll be able to feel it if you are overtraining)
tom, the real truth is everything I do is about looks, I just use my interest in anti-aging protocols as a cover for my narcissism.
My narcissism is longer term and strategic. I'm absolutely baby crazy and every thing I do is so I can fill up a house with kids over and over again for centuries when Longevity Escape Velocity comes.