No up and down the wing. No dump ins. Good hockey players can accelerate their development and optimize their on-ice performance by training specifically for the demands of ice hockey. I have seen too many hard working players who could have achieved more if they had the knowledge of true sport-specific conditioning. It is extremely rewarding to continually hear from players who send word of their rapid improvement.
Most limitations are self-imposed.
Parents have a choice as to what activities they enroll their children in. All of the options for activities and lifestyle and drills and exercises are completely within your control. Parent's decisions are likely made more difficult in that the majority of their peer's kids will enroll in spring leagues and summer tournaments, playing games year round. I always remind myself that following everyone else usually only results in average - you are better to go with what you truly feel is best. You can play hockey games 12 months of the year or play for the winter season and add in three or four different activities as well.