fatigued legs

[laura35]

I have been experiencing my legs feeling tired alot lately with spin class and some runs. I took yesterday off and went for a run today and my legs still felt fatigued even after a rest day. I dont know if it is because I have increased my running from one day a week to 3days a week within the past month. If this is the only reason,then how long should it take for my legs to get use to this routine? I also backed off of one day of bootcamp since I had been increasing mileage,so I really dont understand why my legs are feeling this way. in bootcamp i did alot more intense activities with the lower body and that is why I cut one day back and did spin class in place of that. any suggestions other than another day off. I cant afford to take too many days off, since I need to get a certain amount of mileage in a week for my 12 marathon. thanks