THE HURLINGHAM CLUB, London — Jannik Sinner, the world No. 1 and defending Wimbledon champion, said Wednesday that he is making changes like practising in warmer conditions to try and address the impact of heat on his body and his tennis.The 24-year-old’s last competitive match saw him lose in five sets to then-world No. 56 Juan Manuel Cerúndolo at the French Open. Sinner had been two sets and 5-1 up on a sweltering afternoon in Paris, but an extraordinary collapse saw him lose the next six games, and then 12 of the next 14.In a news conference afterward, Sinner, who was the overwhelming favorite to win the title, said that he had felt unwell before and during the match and played down how much heat was a factor. But the loss followed a similar incident at the Australian Open in January, when Sinner suffered from severe cramps during his third-round match against Eliot Spizzirri.With temperatures approaching 100 degrees in Melbourne, Sinner could barely serve and was struggling to move. On that occasion, the Australian Open’s heat rules meant that the match was temporarily halted and, when play resumed with Sinner down a break in the third after the first two sets had been split, he won the match in four.In high temperatures and humidity at October’s Shanghai Masters, full-body cramps forced Sinner to retire against Tallon Griekspoor and he had to be helped off the court.Why is Wimbledon still played on grass?Tifo SportsSpeaking publicly for the first time since the French Open, at an exhibition event in London, Sinner said that he went for tests after losing to Cerúndolo, to try to understand the root of the problem.“We did some testing, we tried to understand what happened, we came to a conclusion which is very good. So we worked very much, we changed the work a little bit as well, trying to see how my body reacts in different conditions,” Sinner said in a news conference after beating Cameron Norrie 6-3, 6-3 at the Armani Tennis Classic at the Hurlingham Club in southwest London on another baking hot day, when temperatures reached around 95 degrees.“We’ve made some changes in the practice, we made some changes in all other things,” he said.Sinner said he couldn’t predict the future, and that he and his team are doing everything so that the chances of a similar incident to those in Paris and Melbourne “are as low as possible.”Speaking on Wednesday, Sinner said that the boiling hot conditions were good preparation ahead of Wimbledon (where the forecast is for much lower temperatures), and that more warm weather training would be in his schedule going forward.“Today, was no wind at all, so it was maybe even warmer, but it’s good. That’s exactly what I need, a good preparation before starting the tournament.“In future, we will always try to practice where the warmer conditions could be, because I feel like every tournament is getting warmer and warmer every year, so it’s going to be important, but we did a lot of work, and today was a good preparation.”Sinner said that this had been “one of the best preparations I’ve had since a long time before a Grand Slam.” Having played pretty much non-stop between March and May, putting together a 30-match winning streak and hoovering up five ATP Masters 1000 titles in the process, Sinner said he did not pick up a racket for a week after his early exit at the French Open. “I spent some great time with family and friends and that for me was the most important because I don’t have much time to do that,” he said.The exhibition at the Hurlingham, around four miles from the All England Club, also offered Sinner the chance to see how his game feels on grass ahead of his Wimbledon title defense. “I felt quite good today,” he said of playing on the surface. “At the same time, we need to improve a couple of things. It was very warm but physically I felt good.”Wimbledon gets underway on Monday, with Sinner opening proceedings on Centre Court as the defending men’s singles champion.Jun 24, 2026Connections: Sports EditionSpot the pattern. Connect the termsFind the hidden link between sports terms