Possibly but I think it would have to be very gradual. In my case it went from feeling off to not being able to get out of bed within 3 weeks.
I'm trying to work out a time line from my diary.....
17 March 15 I felt ill after running.
22 March 15 felt OK again raced 20m very pleased.
** I then had a couple of weeks of up/down but as marathon training was coming to a end and I'd raced 20m I put it down to that. ****
15 April 15 sore throat/fatigue felt like crap for 3 days
18 April 15 ran a 5k pb in under 18 mins but it was harder work than it should have been.
26 April 15 sub 3 hour marathon but once again fatigued earlier than normal.
**felt pants for 17 days light milage put it down to post marathon (although I'm normally fine the following couple of days after a race. Even after running ultras of 45m) .
****
12 May 15 I've put down total fatigue, no energy and feel awful. Throat is sore again. Once again 3 days and begin to recover.
Then ever since I've been up and down in cycles. Blood tests and Drs plus ran/cycled when I could
13 November 15 sore throat (constant now) fatigued badly and stopped exercise. Feel pants. This was for 9 days.
23 Nov 15 tired, still have sore throat no exercise but not really fatigued like I was, just tired/lathargic etc
****same thing until 26th/27th Dec (I ran) don't feel any worse for running but it was short/slow. But feel mentally better!!
Which is when I found this site.....
Is this similar time line with any others who are keen sportspeople suffering CFS?