A workout every day and a half

I have found that a day and a half between workouts is much better than running every day for me. For example if I run 8 hard miles on Sunday morning it would be very hard for me to wake up on Monday morning and run another 6 miles. I would be too sore and tired. I can however run well by Monday evening. Then following the same plan, my next workout could be Wednesday morning. I'm getting a bit older and can't do a tough workout every day any more and this method seems to work very well for me.