|2||Discuss Workout Techniques||Social interaction|
|3||Endurance Run, Research Workout Tips||Treadmill and computer interactions|
|4||Box, Heavy Lifting||Punching bag and weight machine interactions|
|5||Make Protein Shakes, No Sweat Run||Bar and treadmill interactions|
|6||Show Off Muscles||Social interaction|
|7||Hill Challenge||Treadmill interaction|
|8||Epic Workout||Weight machine interaction|
|9||Practice Fighting||Social interaction|
Fitness is mainly built by using treadmills, weight machines, punching bags, training dummies and by jogging. Sims who are energized will raise the skill faster. If a Sim goes to a gym, they can ask a gym trainer NPC to mentor them, who will then boost the Sim's skill gain by making them energized. At level five Sims can make protein shakes at the bar, that will make them energized. Active Sims will built fitness faster, as they tend to be energized more often than normal Sims. The Bracing Breezes lot trait will also give a 50% boost to fitness skill gain. Like with any other skill, Sims can read skill books to raise their fitness, though this option will not change their overall body shape.
Other emotions also have an special role in gaining fitness. When Sims are angry, they can do rage-fueled runs on the treadmill, enraged reps on the weight machine, blow off steam on the punching bag and swim angry laps in pools. Confident Sims can run with their chest out on the treadmill, or do a roundhouse kick on the punching bag. Both emotions will boost a Sim's fitness skill gain.
Sims who have a high fitness skill can practice fighting with other Sims. The animations are mostly the same as with normal fighting, but Sims won't get any moodlets from it. Having a high fitness skill also impacts the chances of winning a fight.
When a Sim has been working out for enough amount of time, they will become tired and will stop on their own. However, they can still use the "Push the Limits" interaction, but Sims will in the end gain the "Sore" uncomfortable moodlet and cannot anymore workout. As Sims gain more fitness skill, they can workout for longer periods of time, and more workout options will appear. They can perform no sweat workouts to slow down their hygiene decay and endurance workouts to go for longer periods of time, before becoming too tired and sore.
When a Sim has mastered their fitness skill, they can start mentoring other Sims with their workout. Doing this will give the helped Sim an energized moodlet, that will speed up their workout and make it easier. The Sim who is mentoring will get a confident moodlet.
- The child equivalent of fitness is motor, though children cannot learn the fitness skill after mastering it.