As Emma Raducanu arrives in New York for the US Open, she is aware of how hard she will have to work physically to compete at the highest level.
Last month Raducanu became the youngest British woman in the Open era to reach the fourth round of Wimbledon.
But after beating two top-50 players, the 18-year-old retired with breathing difficulties and dizziness when trailing Ajla Tomljanovic 4-6 0-3.
"I think Wimbledon was an extremely positive experience," she said.
"I learnt so much just about my game, and what it takes to perform at the top.