Have played hockey all my life and casually been a gym go'er on and off again for several years. Started going to the gym more seriously as a way to combat stress/anxiety and to prepare for obstacle courses like Spartan Race and Tough Mudder. Having dates set in my calendar for those courses gave me something to set my site on and help both my mental health and motivation.
I'm a Social Worker and all the work I do sees a psychological result of those i support and while I love my work, a lack of 'seeing' completed work can be tiring and working out allows me to physically see results. It allows me to put my music on, get into a non-social work head space and for an hour or so, zone out and simply focus on building something I can see.
and 0after a while, I learnt to enjoy to the 'burn' that goes into working out and that feeling of physical depletion.