Runkeeper was placed on Earth by supreme beings of some sort. Its programmable, GPS-tracked interval runs make the iPhone into a serious, and entirely thoughtless, training tool. But Runkeeper’s ...

You’re looking to push every ounce of energy you have into your current HIIT (High-intensity Interval Training) workout. As the intervals pass you buy, the music constantly changes to fit your tempo.

We like interval training because you can pack a lot of effective exercise into a short amount of time. In fact, you can use it to do one of the most effective routines in only 20 minutes. Regardless ...

For those of you who don't know, I wrote an interval timer app for iOS. A feature request is to allow it to run in the background. Apparently people fidget with their Music or Podcast app enough while ...