There are certainly advantages to both.
I am usually not a morning person but as I was doing JELF last year, I managed to wake up every day at 6 am to go to the gym. This lasted for about 2 months and when winter came, I went unfortunately straight back to my lazy routine.
It’s definitely hard to wake up so early to have enough time for sports, to have breakfast AND to prepare for work but in the end it is worth it. After a morning workout I usually feel refreshed, relaxed, strong and ready for anything, good or bad, that the day might bring.
Working out in the afternoon/evening requires a lot of motivation and strength. I usually work till late in the evening and I am too tired afterwards to do sports, also it will keep me awake till late at night so I have to sleep more in the morning on the next day. It probably doesn’t help that I sometimes forget myself in the office when I am deep into my work and it gets so late that I decide to skip sports altogether. I started recently to set up alarms on my phone when it’s time for me to go home and it seems to work most of the times.
Last time I planned to go to the gym after work and failed was a few weeks ago, perhaps even a month! I decided then to leave my sportsbag in the office overnight to go on the next day but I eventually forgot all about it and the bag is still in the closet at work waiting for me to use it.
Another reason why my sportsbag is still untouched is because I currently prefer working out in the morning before going to work.
I decide what I want to do and prepare everything the night before. If I manage to wake up on time, which happens most of the times thanks to my alarm because I am not a deep sleeper, I only have to jump into my workout gear and I am good to go. The first few minutes before I feel fully awake are always tough but it goes smoothly afterwards. Plus when I go running outside, the fresh morning air wakes me up instantly! It only takes 30-60 minutes and it brightens my entire day!