Not everyone is an early riser. Some people are naturally early morning people. It is easy for them to get up, even before the sun is up. If you are one of those people, I would strongly encourage you to do your exercise then. It is the least likely time you will be interrupted by anyone. You are able to mark your exercise off your “to-do” list for the day. It is a great way to establish a positive attitude for the day.
If you are not an early riser, it is OK to do your exercise later in the day, when your body feels most awake. The most common issue I see when people delay their exercise until later in the day is that there are so many more chances of interference happening, and if you really are not fully committed to your exercise, the smallest excuse may arise and this may prevent you from exercising. You need to be determined to stick to your plan for the day and not allow excuses, and a “better offer” to take priority.
Commitment, appointments and accountability help to ensure your exercise is maintained. This is a contributing factor as to why training with me works; you have made a commitment to me, and I have made a commitment to you.