Quickstudies (or Gestures) can solve this problem. Quickstudies are poses that range in time from 30 seconds to 3 minutes. When doing quickstudies pay as much attention to finding the line of action as possible. At first it will be difficult, but learn from your mistakes and after a while it will make drawing the figure a lot more fun. These examples are mostly from the 1-3 minute timeframe--->
The great thing about Quickstudies is that you don't have enough time to work on anything that's not important.Rhythm can't be taught in the same way as anatomy because the rhythm changes completely based on the pose and no one part of the body has the same rhythm for every pose. On top of this, what you choose to emphasize can be subject to the artist's opinion. In a pose that's lacking clear rhythm, 2 different artists may push the rhythm in separate ways in their drawings (like quantum mechanics ;)
Skills learned doing quickstudies will immediately translate into more lively drawings for longer poses. Like everything else, results can't be achieved without practice and patience.