Are 10,000 steps enough?

A "Fit-Bit"--my hi-tech pedometer--has a base goal for total number of steps per day:  10,000 steps.  I can change this goal anytime I want.  But is 10,000 steps enough?

It depends.  According to The First 20 Minutes, by Gretchen Reynolds, 10,000 steps is enough exercise if all I'm trying to do is to live longer.  Couch potatoes have a much greater chance of dying young than active people.  As you become more active, your chance of living longer keeps increasing.  But most of the gains are achieved once you reach about 20 minutes a day of moderate activity such as walking 4 miles per hour.  You need to exercise more minutes if you exercise more lightly, and fewer if you exercise intensely.  But, overall, you can be pretty sure to have more than enough if you walk 10,000 steps.

Further, it apparently doesn't matter much how you accumulate the steps through the course of the day.  Bringing the laundry up from the basement, climbing stairs to your office, walking to a meeting--it all counts.  So having a pedometer is a great way to see whether your approaching or exceeding this goal.

But what if you want to do more than just outlive a couch potato?  What if you want to lose weight?  Get stronger?  Build your agility and endurance?  If you also want to do these things, 10,000 steps will NOT be enough.  You'll need intense cardiovascular exercise and resistance training.  If you want to be more flexible, you'll need to stretch or do yoga.  But the 10,000 steps is still a good starting point, a base level of activity that is likely to lead to a longer life.  I can take these steps and then add weights, yoga, or cardio.