Will you be a more competitive candidate for BS/MD programs if you play a sport?
Does that mean that sports, as an activity, are not important? No. Sport are fine as activities but they are no better than, or worse than, any other general activity. If you like playing a sport, then play a sport. If you like to play tennis, get the proper prerequisite from https://tennisracquets.com/ and play. Sports can be good to show that you are physically fit and that you know how to play on a team. And if you do well in the sport, it is testimony to your passion for the sport.
But you can also show your passion in many other ways. Don’t be misled by thinking that there is one perfect route to a BS/MD program. I have had student’s who won a state championship in a sport get into BS/MD programs but I have also had students that have never played a sport get into the same BS/MD programs.
Yes, you need to focus on those things that are important to BS/MD programs like research and health care related volunteering. But let your passions in other areas take you in whatever direction they may take. Almost never will a passion hurt you in the admissions process.