Avoid pain on the bicycle by addressing postural strains
Bicycle-related postural strains are the most common pain complaint with endurance bicycling, most frequently occurring at your spine and shoulders.
Postural strains present as discomforts in the musculature, much like the feeling you might get if holding a push up position for 10-20 minutes.
This discomfort makes holding a particular position on the bicycle difficult. You may find that you are frequently changing positions or have the urge to take a break off the bicycle to avoid discomfort. The discomfort is alleviated by standing up on the pedals and coasting, or by simply getting off the bicycle entirely.
A simple postural strain has no residual pain once off the bicycle, which leads you to either forget about the pain until it becomes chronic, or to associate the discomfort with being on the bicycle (which in turn can lead to not riding your bike). Postural strains have transitioned into chronic injuries when the pain persists off the bicycle.
The good news is, examining your position on the bike is the easiest way to manage postural strains and avoid chronic injury. Most postural strains on the bicycle are bike fit related.
The appropriate bike fit fix will seem almost magical. You will be able to ride reasonable distances with far less (and possibly even no) discomfort than previously experienced. You will be able to maintain your position for greater periods of time and your confidence on the bicycle (handling and safety) will improve.