Riding a stationary bike is boring, but gives you a workout. Video games are engaging, but makes you obese. We're starting to see them converge.
From the video game side, the Nintendo Wii is holding its own against Playstation 3 and XBox 360. Here are some more innovative examples.
From the exercise side, more gyms are starting to install stationary bikes with video game monitors where you go your actual speed, and compete against other riders. This causes people to (1) ride faster, because they're competing, and (2) be more willing to go to the gym, because it's not so damn boring.
Most people's workout routines are cognitively sterile. Here are a few ways to make it more engaging:
1. Work out with other people
2. Compete against others, (or yourself, by times or weights)
3. Exercise outside
4. Increase the variability of your exercises
5. Shorten your workouts (but compensate with higher intensity)
6. Add (a little) danger to your workout (headstands, rock climbing, etc.)
7. Play video games that simulate these qualities
The hunt was physically and mentally demanding. As was battle. A quality we need to regain.