How Much Exercise Do You Really Need?

Recent health headlines tell us that women need to exercise for an hour each day to avoid gaining weight! An hour? Every day? Seriously? That's 7 hours a week!

Surely that can't be. Previous recommendations have urged us to exercise 150 minutes a week, which works out to 2 ½ hours weekly.

Related: Exercise Less, Burn More Calories

And we do still need that much every week, but for other health benefits. The federal government recommends that we get at least 150 minutes of moderate-intensity aerobic physical activity each week. This "consistently reduces the risk of many chronic diseases and other adverse health outcomes," according to a major 2008 guideline from the US Department of Health and Human Services.

While it is great to reduce one's risk of chronic disease, this amount may not be enough to ward off the extra weight that people typically gain as they age. In a recent study, researchers followed more than 34,000 healthy American women, who were roughly 54 years old. While following their usual diet, the women gained an average of 5.7 pounds over the next 13 years. The researchers found that the women who kept a normal weight did so with a lot of physical activity.

Related: Booty Beauty- Easy Boost For Those Glutes! (video)

The women who got 420 minutes (which is 7 hours) of physical activity a week gained significantly less weight than the women who got less activity. Interestingly, the 420 number seemed to be a tipping point: Women who did 150 to fewer than 420 minutes of weekly activity gained as much weight as those who were physically active for fewer than 150 minutes!

Another interesting finding was that the relationship between more physical activity and less weight gain was seen only in women with a normal weight. This connection didn't hold for women who were already overweight or obese.

The take-home message? To keep weight off, you have to keep moving. 150 minutes a week? Nah. Let's make it 420…minimum.

How much exercise do you get...and how much do you need to do to LOSE/KEEP OFF weight?