This is very good to see having Strength and Flexibility in the same sentence...
Flexibility is overlooked loads when people focus on strength hence seeing some guys in the gym that have this hunched up gorilla posture about as much flexibility and range of movement as a plank of wood!
loosing any range of movement can hinder the body in all sorts of ways as if a muscle shortens in one area another has to compensate to make ends meet causing an inbalance and this is where injuries can happen.
doing a little stretching each day can be a huge benefit.... I have actually been coming from a gym and saw a rather large musclular guy (you know the type huge arms, back, chest and tiny legs) drop his keys and well it was not pretty seeing how he had to "try" and bend to pick them up.
setting aside active recovery days to do a full body strech session can help limit injuries and keep range of movements good. one of the best pieces of kit i have ever got is a foam roller that can help to stretch out on a more localised area those hard to reach spots.
these can be picked up for as little as £10 and will last years... can google all the exercises.
Active Every Day: Ides of March