Yoga is just one of the parts of it! It also has balance games, aerobic games, muscle games (The game has about 40 different activities, including yoga poses, push ups, and other exercises.)
Here is a blurb fro wiki...
Activities
Training on
Wii Fit is divided into four categories: aerobic, muscle workouts, yoga poses, and balance games. The activities provide a core workout, emphasising controlled movements rather than overexertion. Activities include:exercises, ranging from deep breathing to extended poses.
Yoga, Muscle workouts, including press-ups, sit-ups, and twists. Aerobic exercise., in two formats: fixed distance, and fixed time.
- jogging
- Step aerobics- Three types.
- hula hoop- Basic and super.
- Rhythm boxing - similar to step aerobics but including the Wii remote and nunchuk to throw punches.
- Balance games
- Ski Jumping
- Ski and snowboard slaloms.
- Heading footballs.
- Table tilt - Where the player shifts their balance to get balls into holes.
- tightrope tension - The player must cross a tightrope avoiding the snapjaws.
- Balance Bubble - The player attempts to navigate down a river in a bubble without bursting it on the sides.
- Penguin slide - The player has to catch fish whilst balanced on a piece of ice.
- Zazen - The player must remain motionless whilst looking at a flame.
Some of the games allow the player to watch TV while getting instructions or rhythm through the Wii remote Speaker.
New activities can be unlocked by gaining 'Fit Cash', which is accumulated in a 'Piggy'. Each minute of Fit Cash is equal to the number of minutes doing an activity rather than the number of minutes of overall game play. At certain stages, new yoga poses or muscle workouts are unlocked based on the total time spent working out. Being the best at an activity with a 100% score, or playing an activity a certain number of times unlocks more rigorous versions of that activity.