When Alexander Zverev steps onto the court, he’s not just managing serves and rallies; there’s another clock he’s constantly aware of. A quieter one. The need to monitor his blood sugar levels throughout the match.

It’s a challenge he often describes as “two games happening at the same time.”

While he may still be chasing his maiden Grand Slam, a few players embody resilience like the German.

The 28-year-old endured another semifinal heartbreak at the Miami Open, falling to Jannik Sinner. Yet beyond the result, his ongoing battle with a lifelong health condition resurfaced, once again capturing attention from the fans.

A fan recently shared a video of Zverev taking insulin during a changeover at the Miami Open semifinals. Zverev has lived with insulin treatment since being diagnosed at just four years old. 

Fans rallied behind him after the video surfaced. Many praised his strength and resilience, sharing it with the tagline, ‘Reason #2 Why Zverev Deserves More Respect’.

On tour, the German carefully manages his condition. He regularly monitors his blood sugar levels before matches, during changeovers, and after play when needed. Managing energy during long matches is challenging. In physically demanding five-set contests, glucose levels can fluctuate, making constant monitoring essential.

To maintain balance, Zverev relies on insulin injections. At times, he administers insulin during matches to keep his blood sugar stable.

He has been seen injecting insulin on court during changeovers. This step is necessary to prevent dangerous drops or spikes that could lead to dizziness, fatigue, hypoglycemia, or even serious medical emergencies.

The 28-year-old publicly revealed his diagnosis in 2022. Before that, he had kept it private for most of his career and described managing diabetes during matches as playing “a second match” alongside his opponent.

He once explained his journey with honesty, “Becoming a professional tennis player was always my dream. Early on, I was told that competing at the highest level with diabetes was impossible, but my family and I refused to accept that.”

Instead of letting diabetes limit him, Zverev used it as motivation. He went on to achieve major success, including reaching World No. 2, winning Olympic gold, and claiming two ATP Finals titles.

His impact goes beyond tennis as well. Through the Alexander Zverev Foundation, launched in 2022, he supports children with diabetes by providing insulin, promoting active lifestyles, and fighting stigma around the condition.

Last year, he also took part in charity efforts before the Davis Cup Final 8, playing an exhibition match against diabetic player Patrick Zahraj, and later hosting a gala night in December to raise awareness and support. 

And although even as fans now draw inspiration from his visible insulin use in Miami, Zverev has previously faced serious challenges on tour while trying to manage his condition during matches.

Alexander Zverev voices frustration over French Open diabetes stance

In 2023, Alexander Zverev reached the quarter-finals of the French Open with a straight-sets win over Grigor Dimitrov. The result looked comfortable on paper, but the situation during the match was far more complicated.

The issue centered around his medical needs. Zverev was told he could not use his insulin pen on court during the match. Instead, he was instructed to leave the court for injections. These exits were counted as limited toilet breaks, creating additional pressure.

Zverev spoke openly about the situation. “On the ATP Tour, I do it on the court, here they don’t allow me to do it,” he told Eurosport Germany.

He explained the difficulty it created during matches. “I’m not allowed to do it on the court, and I have to run out every time. Then, at the last match, I was told that it counts as a toilet break. That’s when I said, ‘guys, I might have to walk off the court four or five times. Decide what you want me to do’.”

He also described confusion during an earlier match. Against Frances Tiafoe, a supervisor did not understand his condition. Zverev recalled the moment clearly. “I then gave myself an injection, and he panicked and said I had to call a doctor if I gave myself anything.”

The situation quickly gained attention beyond tennis. There was strong backlash from the global diabetes community, who supported Zverev’s position. Following the backlash, officials at the French Open reversed their stance and allowed Alexander Zverev to inject insulin on court. 

And as he now balances his career and condition, Zverev heads into the clay swing as a source of motivation and inspiration.