goals are necessary to prevent injury

Strength, conditioning and skill are components of all physical training programs and setting goals determines which of these three categories will be emphasized.  Your goals should be as specific as possible so your coach can design a program that helps you reach your objective while minimizing the risk of injury. 
I like martinis and I also like cranberry juice but I don't like to mix the two (a Cape Cod).  A martini is made with either gin or vodka with a touch of vermouth.  It is incorrect to call either of these spirits a martini when mixed with anything else, such as cranberry juice, and poured into a martini glass.  The same should be true for your workouts.  If you are performing strength training exercises with >75% of your maximum load at a rapid pace you have crossed the line into the realm of confusing strength training with conditioning which will likely result in injury.  If you want to become a better tennis player practice your  backhand repeatedly and hire a good tennis coach but don't try to replicate the movement with a dumb bell - studies show that this is not effective.  Mastering specific movements required for a sport should not entail weights (unless you are an Olympic or power lifter) nor should these movements be approximated.  The action should be pure and closely observed.  For conditioning, a lighter weight and more repetitions should be used than in strength training.  When used in combination all three of these modalities make you healthier, stronger and increase your cardiovascular endurance.  We all recognize this activity as cross-training.  The challenge lies in knowing the difference between the three subsets and modifying your routine when the lines between the three have blurred.