Yoga
Yoga is a fitness-building self-interaction that Sims can perform. Yoga is present in The Sims 2 and The Sims 4: Spa Day.
The Sims 2
Sims who have three or more body skill points can perform the "Do Yoga" self-interaction. Yoga builds Sim fitness and body skill. There is also a related secret yoga skill, but skill at doing yoga is related to Body skill, not yoga experience. Sims with higher body skill perform more advanced yoga positions, and are less likely to lose their balance and fall over, which will cause them to stop. If a Sim is doing yoga, other Sims can join, regardless of their body skill.
A visibly pregnant Sim cannot perform the "Do Yoga" self-interaction, but can join a Sim who is doing yoga.
Unlike many activities that build body skill, yoga does not cause a fast drop in the Hygiene meter. Also, if Seasons is installed, yoga does not raise a Sim's temperature. If FreeTime is installed, yoga builds enthusiasm for the Fitness hobby. Yoga uses similar poses used in the Meditation interaction, and adds other poses, such as the Headstand.
The Sims 4: Spa Day
Performing yoga builds a Sims' wellness skill. Yoga is performed using a yoga mat. Yoga can also be learned from a yoga instructor.[1]
If Sims practice Yoga often enough, they will become fit and muscled. To train the wellness skill without making a Sim muscled, try using massage or Meditation.
The Yoga Mat has options to do a Yoga routine, practice Yoga, and do individual poses. Practicing yoga and doing poses only boost fitness and the Wellness skill, but Yoga routines give different moodlets.
Doing the routines gives a +1 moodlet based on the routine that was chosen, There is also a chance to get a Confident moodlet, because the Sim is getting fitter by performing many Yoga poses. Doing the Mind Concentrating routine will get the Sim Focused, which allows them to build the Wellness skill faster. These are the three routines:
Brain Boosting: This will give Sims an Inspired moodlet for 8 hours.
Mind Concentrating: This will give Sims a Focused moodlet for 8 hours.
Energy Centering: This will give Sims an Energized moodlet for 8 hours.