I noticed this as a soft lump in my stomach at the end of September. Since then I tried a week of rest, and that didn't help (or hurt), so I went back to training. I was at the end of my cycling program - where I'm supposed to take a break, or switch to strength training, so I switched to strength training.
I'm following a CrossFit type program of body-weight exercises. I've got 1/2 of the garage taken over with benches, steps, medicine balls, and a pull-up contraption thing. I'm really enjoying it, and I'm missing the bike less than I thought I would be.