There are various types of TRAINING that you can do to make yourself stronger in the game. TRAINING gives you special power-ups that improve your performance during a fight. But these boosts are time bound and deplete over time, all at different rates, so you have to keep training regularly to get optimal benefits. 

Following type of Power-ups are given by different TRAININGS:

AGILITY
You can improve your crew's AGILITY by training in FIGHT CLUB. This training consumes STAMINA and trains your crew to be faster during fights... in effect it boosts your crew's total ATTACK POWER (equivalent to 25 SKILL POINTS). 

ENDURANCE
You can improve your crew's ENDURANCE by training in GYM. This training consumes STAMINA and trains your crew to take heavy hits during fights and last longer... in effect it boosts your crew's total DEFENSE POWER (equivalent to 25 SKILL POINTS) 

ACCURACY
You can improve your crew's ACCURACY by training at SHOOTING RANGE. This training consumes STAMINA and ENERGY both. It trains your crew to do critical precision hits during fights against almost equivalent opponents by improving the accuracy of your crew's armory by 25%.

VEHICLE TACTICS
You can improve your crew's VEHICLE TACTICS by training at RACE TRACK. This training consumes STAMINA and trains your crew to manage Vehicles better... in effect it boosts the power of Vehicles by 25%.

ARMOR TACTICS
You can improve your crew's ARMOR TACTICS by training at MECH SHOP. This training consumes STAMINA and trains your crew to handle Armors better... in effect it boosts the power of Armors by 25%.

WEAPON TACTICS
You can improve your crew's WEAPON TACTICS by training at PRIVATE MILITIA CAMP. This training consumes both STAMINA and ENERGY. It trains your crew to handle Weapons better... in effect it boosts the power of Weapons by 25%.