There is a strong correlation between exercise and a decrease of anxiety and depression. It is a short term side effect for sporadic workouts, and long term for those that exercise consistently. Group exercise creates an environment full of energy, and working out with a partner creates more motivation.  Trainers and fitness instructors are there to guide you, however you should be knowledgeable yourself so you have a sense of autonomy.

Another reason a group setting or a workout partner are beneficial is, because people with low efficacy are twice as likely to injure themselves, so having competition can increase motivation make you more accountable for your actions, decreasing the risk of injuries. Feedback from a partner can also help you stay safe and focused. Perception also plays a role in motivation, if an or goal action seems difficult, it will be. Keep it simple, remember that you are a part of culture/tribe, and keep yourself and others motivated!