The most obvious problem faced by a Seventh-day Adventist who wishes to participate in organized sports is the tendency for games to be scheduled during Sabbath hours. Competitive sports and Sabbath observance are often not compatible with one another. Another challenge at higher levels is pressure to take performance enhancing drugs (doping).
An alternative that avoids Sabbath breaking or drug pressure would be to participate with a group of like-minded individuals. Many towns offer city leagues, and it may be possible to form a team with other members of your church, with the understanding that you will not compete on the Sabbath. The Adventist athlete may also enjoy individual sports instead, or engage in informal pick-up games. A student choosing an Adventist University or College which offers team sports programs is unlikely to experience Sabbath difficulties.
As Christians we need to show Christ-like behavior on the field. Always play fair and be a good sport. Don't trash talk other teams or players. It is OK to try to win, but not in any way that degrades or sets a bad example.