Persistent Sore Muscles?

Maybe it's a lack of Vitamin D.

If your muscles feel sore or you keep on being injured when you exercise, get a blood test called D3. If it is below 75 nmol/L, your problems may be caused by lack of vitamin D and be cured by getting some sunshine or taking at least 2000 IU each day of the very inexpensive vitamin D3.

Or, it just might be that the group you ride with never takes an easy day.