There have been times where I worked out hard on a Monday, Tuesday and Wednesday and then took the rest of the week off, believing that at least I worked out three days that week so that's a good as anything else.
But in the back of my mind I knew I felt physically better when I spread it out to, say, Monday, Wednesday, Friday and Sunday. My body felt more fluid and I didn't have any of the stiffness than even a five day break can bring.
Turns out my gut feelings may be correct.
While not as extensive as the EmpowHER ASK/SHARE Community the New York Times has a forum where some questions can be reviewed and this topic was one of the them.
With regard to an exercise question about the regularity of exercise, The Times reported a response from Dr. Michael Joiner, a physiologist from the Mayo Clinic. Joiner said yes, it's better to spread out exercise over the week rather than try to fit it all in within the first few days.
The reasons for this, he said, are that while exercise brings immediate good effects to the body like raising the heart rate and stabilizing blood sugar, there are also long term effects that will happen more when we exercise on a consistent basis. Some of these benefits are like stamina, and the "high" one gets from raised endorphins and feelings of contentment that exercise brings.
Regular exercise (every other day, for example) can also lessen the risks of injury to muscles. Also since we are creatures of habit, every other day may have us coming back consistently, as opposed to "binge-exercising" that doesn't fit into our nature of establishing habits.
Dr. Joiner cited animal studies involving mice that concluded with similar findings. When the mice were not allowed to use their exercise wheels consistently, they showed signs of being less fit within days.
EmpowHER has a lot of information on the benefits of regular exercise including how important exercise is as we get older.