from dr. mercola.com
What’s the Ideal Dose of Exercise for Optimal Health and Longevity?
Research has shown that once you reach 40 to 50 minutes of daily vigorous exercise, or just over an hour of moderate exercise (such as walking), the benefits from your efforts plateau, and further efforts do not convey additional improvements in life expectancy.
One of the largest, longest, and most recent studies5 to shed light on this “Goldilocks zone” found that those who walked or engaged in other moderate-intensity exercise for 450 minutes per week (right around one hour per day, seven days a week) lowered their risk of premature death by 39 percent compared to non-exercisers.
Those who exercised around 3.5 hours a day only reduced their mortality risk by 31 percent — the same risk reduction as those who met the guidelines of 150 minutes per week (about 20 minutes per day).
A second large-scale study,6 which focused specifically on intensity, found that spending 30 percent of your exercise time on strenuous, high-intensity activity can gain you an extra 13 percent reduction in early mortality, compared to never picking up the pace and breaking a sweat.
When it comes to endurance cardio, previous research (discussed in the TED Talk below) has shown that to optimize the health benefits from running you’ll want to run 5 to 20 miles per week — the ideal amount being 10 to 15 miles per week. Once you reach 25 miles or more per week, the benefits again disappear.
Also, if you run too fast — over 8 miles an hour — the benefits tend to go away (note we’re talking about speed in long distance endurance running here, not interval sprinting). Lastly, if you run seven days a week, the benefits also disappear. The ideal amount was found to be a 30-minute run, two to five days a week.
So, the key really is moderation — moderation in terms of intensity, duration, and frequency. The human body simply wasn’t designed to engage in long-term extreme athletic performance, like battling ocean waves for 8 hours a day for six months straight.
but for someone like myself who simply wants to taper off, getting my ass moving for 45 minutes/ five days a week is such a chore.