These activities cause dysfunctional patterns of tightness in our musculature because the same muscle groups are used repetitively again and again and again in the same posture! The solution to most of these problems is not strength...as most of us are strong to begin with. It involves the quality of the soft tissues...the muscles, ligaments and supporting structures. Most therapy practices that don’t understand runners and triathletes treat the symptoms of pain but not the causes. Thus, the tissues stay tight and restricted and performance suffers.
Think of this...how often do we stretch, massage and drink plenty of water to take care of our musculature?