There are many Trainings available in the training tab
Punching- Increases the player's Speed stat.
Cutting- Increases the player's Precision stat.
Painting- Increases the player's Sense stat.
Camping- Increases the player's Instinct stat.
Smelling- Increases the player's Taste stat.
Reading- Increases the player's Intelligence stat.
Spying- Increases the player's Idea stat.
you can fight challengers in the training tab, fighting challengers requires beating the museum district.
After completing the office district you can buy upgrades which act as a multiplier for your stats. Each purchase increases the cost of the next upgrade.
Boxing center- Increases Speed by 5% per level.
Dojo- Increases Precision by 5% per level.
Museum- Increases Sense by 5% per level.
Rain Forest- Increases Instinct by 5% per level.
Spice Testing Center- Increases Taste by 5% per level.
Library- Increases Intelligence by 5% per level.
Ninja Training Center- Increases Spying by 5% per level.
It is a good idea to train all trainings equally. Setting next at to 1 will cause the trainings to move one after another indefinitely.