Weight training can and should help athletes of all levels have a long and productive career. When done properly, an athlete can expect increased strength, speed, quickness, and agility. To extend your playing career not only means more dominance over a longer period of time but it also means more $ for professionals.
One of the fastest ways you can end or shorten your career is by doing explosive or a fast style of weight lifting. These would be the power cleans, squat jumps with weight, and any exercise that the actual speed of the weight is fast. These examples are the least productive type of training. The rationale being if you move the weight fast it will improve explosive power and speed. This is completely false. An individuals body proportions(length of muscles, bones, connective tissue) and ability to activate a high percentage muscles quickly is genetic and programmed by the central nervous system. You can't change your genetics! There is nothing you or I can do about it. Any effort in trying to do exercises to change this is a waste of time at best. At worst you can suffer a catastrophic career ending injury.
This holds especially true for younger athletes that are still developing. I recently was contacted by the parents of a top high school water polo player. They found out that there son's coach was having them do power cleans as a part of his training program. Power cleans...for water polo?! Following their intuition, they didn't feel right that their son was doing power cleans and had him come meet with me. After learning how his coach had him and the rest of the team weight train, I was troubled but not surprised. Doing explosive training puts your body's connective tissues, muscles, and joints under tremendous force. Force causes injury.
Recent so called training "advances" such as flipping tires, circus balls, parachutes, rubber bands, heavy ropes,
and explosive training have "advanced" athletic training to the horse
and buggy era. Why do athletes do them? I have no idea but it's a sure way to put more wear and tear on your body than ever before. It's a great way to end your career early!
To get the most out of your athletic ability, build your strength/size as needed for your particular sport/position by weight training very hard, briefly, and infrequent as outlined on this blog. Then do sport/position specific skill training that your sport requires. Skill training that involves the exact actions necessary for what you're doing on the field.