Alexander Zverev couldn't follow his first Grand Slam victory at Roland Garros with another title: on Saturday, he fell in the semi-finals of the Halle Open in Germany against Taylor Fritz, in three sets, where Fritz later lost the final to Frances Tiafoe.
The match with Zverev was very tight, 7-6(4), 4-6, 5-7, but the German suffered on court, requiring a medical timeout. He later explained that he suffered something that had never happened to him: his sugar glucose sensor failed, showing he had much higher levels of glucose that he actually had. When he tried to fix, drinking glucose drinks, it was too late for him to maintain his strength during the match.
"I had huge problems with the sugar because the sensor I use gave me a completely incorrect reading. It indicated very high values when they were actually low, so I injected much more insulin than I should have", Zverev said. "During the match, or rather during the first 45 minutes, I had to consume about 350 grams of sugar. That is very hard to manage. It's like someone drinking a huge amount of soda during a match. I felt absolutely terrible."
Zverev did credit Fritz, saying he deserved to win that day, but was frustrated because it was the first time since he uses this sensors in 2016 that it had shown such an error.
Zverev, now 28 and considered one of the best tennis players of his generation, was diagnosed with Type 1 diabetes at age 4, a condition that would have put many other players away, but not him. "There are two games happening at the same time: there's the match everyone sees and the one only I feel. If I don't manage my diabetes properly, I can't compete at the level I expect", Zverev told Reuters before Australian Open 2026 (via Sportshadow). In 2022, he opened a foundation helping kids get life-saving insulin.