Possible Clues:

• Athlete's goal
• It's the best you can do
• Display of a person's absolute best
• Athlete's A game, and a hint to the first words of 3-, 5- and 9-Down
• Display of one’s very best
• Stage presentation about mountain climbing?
• Fulfillment of an athlete’s training
• Athlete's goal in competition
• Athlete's A game
• Payoff of athletic training