Keeping cool as Wimbledon temperatures soar

Tennis is not considered to be an extreme sport, but when players are exposed to high temperatures for long periods of time, the consequences can be severe. With temperatures expected to reach up to 34 degrees this week, tennis player and Nuffield Health and Wellbeing Physiologist, Sam Pool, has some tips to help players and spectators keep their cool.

In January last year, spectators at the Australian Open watched on as professional tennis players collapsed in 40 degree heat. The competition came under fire from players and fans alike, including British Number One, Andy Murray.

A new heat policy was introduced for the Open at the beginning of the year. Wimbledon organisers have implemented their own ‘heat rule’ as things heat up on court this week.

The rule allows women’s matches to be suspended for up to 10 minutes between the 2nd and 3rd sets if a ‘Heat Stress Index’ - which combines humidity, air and surface temperature -exceeds 30.1 degrees. But the rule doesn’t apply to men.

Health and Wellbeing Physiologist, Sam Pool, from Nuffield Health’s Fitness and Wellbeing Centre in Tunbridge Wells was a performance analyst at Wimbledon in 2012 and 2013 and is a competitive club player too. He knows only too well the strain the pros will be under.

More protections needed

“The kind of scenes we saw in Australia in 2014 show why heat rules should be in place for all players,” he says.

Umpires there can now suspend play during any match if conditions become too severe.

Wimbledon matches – especially men’s matches – can be famously long. In 2010, records were smashed when John Isner and Nicolas Mahut battled it out for over 11 hours.

“When extreme heat is added to the mix, players at all levels can be put under immense physiological strain,” says Sam.

It is common to see sweat rates of up to two and a half litres, “top players will know their own sweat rates and the concentration of sodium in their sweat,” he says.

Elite players are helped by sports nutritionists and scientists to rehydrate and replace lost energy with personalised carbohydrate-electrolyte drinks.

A loss of sodium through sweat can cause muscles to cramp, fatigue, and a rise of core body temperature. Players can lose up to two per cent of their body weight during a match as water leaves the body. It can take a serious toll on the body, limiting muscle strength, reaction time, and cognitive ability.

“You can see players suffering in the heat begin to make bad decisions. They play erratic shots and make unforced errors. They’ll try to shorten the point anyway they can.”

Luckily Wimbledon is the only Grand Slam event to be played on grass, “it leads to quicker pace of play and generally leads to shorter rallies compared to other surfaces like clay,” he says.

But anyone playing in the heat, on any surface, needs to keep their cool.

How to keep your cool

“Players should drink 400 to 600ml of cool fluid two hours before their match, but with warms ups and pre-match exercise they’ll need to exceed these guidelines,” Sam warns.

“Professional players have a support team to keep the player’s fluids topped up with 200 to 400ml of carbohydrate-electrolyte drinks with high sodium concentrations at change of ends and between sets.”

But an endless supply of fluid isn’t a complete answer. Over-salted drinks can be unpalatable and drinking high volumes of fluid while exercising can cause gastro-intestinal discomfort.

Elite players are often seen draped in ice collars which “help skin temperature to drop and greater dissipation of the core body temperature” - a central cause of fatigue.

“These are proven techniques, but you can only push the body so far, especially in the heat. It would be useful for a gender-neutral heat rule to be in place at Wimbledon,” says Sam.

“While on court temperatures at club matches can’t be accurately measured, umpires and coaches need to keep a close eye on their players.”

It is likely spectators will also suffer in the heat.

“15,000 tennis fans can squeeze into Centre Court, with the lower tiers exposed to direct sunlight. On the outer courts spectators often have to stand shoulder to shoulder.”

Sam was lucky enough to watch Andy Murray claim victory at Wimbledon in 2013. During that match scores of spectators were treated for dehydration, sunburn and heat exhaustion.

“You’ve got to seek shade every now and then. Have a cool drink and eat regular snacks to help maintain blood sugar levels, especially if you’re drinking alcohol.”

Last updated Wednesday 16 September 2020

First published on Wednesday 1 July 2015