title: GPS V.S. accelerometer to calculate distance
body: <p>I am trying to implement a fitness app that can keep track of the running speed and running distance in Android. </p>
  
  <p>It looks like I can either use GPS or Accelerometer to calculate these information.</p>
  
  <p>Since a runner may put his phone in hand, on the shoulder or in his pocket, my first intuition is to use GPS to get locations and calculate running speed and running distance. But recently someone telled me that I can also use Accelerometer also does that.</p>
  
  <p>My question is: In Android, which approach is better to calculate running speed and running distance, GPS or Accelerometer?</p>