The opening weekend of racing at the Tour de France has been fiery in more ways than one. On the bikes, riders haven't failed to put on a show, but the biggest battle many riders faced was one with Mother Nature, rather than each other. As the race began in Florence, a high-summer heatwave blasted Italy, turning it into an oven.
Mark Cavendish was the highest profile rider to suffer, vomiting en route and, at the finish, being given an iced towel by a waiting press officer. It was already going to be a tough day for the British sprinter with 3600m of climbing on the road to Rimini, but the 36°C heat didn't help.
Light winds on Sunday did little to dissipate the heat, instead turning the Adriatic coast into a convection oven. The weather might have been perfect for the hoards of holidaymakers in nearby seaside towns, but among the crowd of fans at the start in Cesenatico, teams were frantically equipping their riders with cooling aids.
Ice vests were a common sight, ice-slush drinks were downed, popsicles were plentiful, and almost every rider started the race with at least one ice sock down their jersey. Riders were even stuffing water bottles down their jerseys for a moment's respite from the roasting they were getting.
To get an understanding of the science behind the cooling techniques, as well as an insight into each team's techniques, Cyclingnews spoke to a few teams at the start of stage 2 in Cesenatico.
Ahead of the race, the primary focus was on acclimatisation for all teams. The difference that heat adaptation can make is significant. Speaking to Cyclingnews before the Tour, Red Bull-Bora-Hansgrohe's Head of Performance, Dan Lorang, gave an example of the potential benefits of heat acclimatisation.
"Your threshold is say 400 watts. In hot conditions, it could be that the threshold drops to 370 for example. With heat adaptation training, you probably can bring the threshold back up to 390 or 95 somewhere there, so you can close that gap."
If this were an equipment change, a saving of 20 to 25 watts is something that teams would pay significant amounts of money to achieve, so the benefit of acclimatisation, and then subsequent cooling strategy, is huge. It's no surprise to see teams investing in new technologies and staff support in this area.
"The world's warming up, that's clear," began Ineos Grenadiers DS Zak Dempster matter-of-factly.
"The body's response to the heat is something that's been written about a lot, and it's part of our preparation process, because of the positive effect it has on the training stimulus to be more ready. Our guys do a lot of heat training, a lot of them have heat chambers at home, which they go in, and that's a big part of our process."
At Team DSM-Firmenich-PostNL, the Head of Science, Narelle Neumann, explained that this process begins around three to four weeks prior to the race for her riders.
"For some riders, they do it on the bike so will be wearing extra clothes, because we want that extra stressor while they're training. For other riders, it's better to do it after, during recovery, so that it doesn't compromise the training. For those riders, they'll either do a sauna session or a hot bath session. The key here is we also monitor how much they sweat so that they can keep hydrating so that it doesn't compromise the next day."
The preparation phase doesn't stop until the very moment the race begins, and even during the week leading up to the race, with Florence such a furnace, the riders would have been adapting and acclimatising right until the very last moment.
"When we got here to Italy, in the days the training days beforehand, we were using all of our hot weather protocols," Neumann continued. "The drinks we adapt for hot weather so that they can drink more without having too much carbohydrates, also ice socks.
"I think yesterday was a great example of what we can do in the race to make sure that all of the riders are really well-fueled and stayed cool. We had, I think, more than 10 bottle points, with a lot of support from staff with bottles, ice slushies and ice socks. It sounds a little bit traditional, but it's still the most effective way to cool."
Dempster also pointed out that when it comes to cooling, things needn't be unnecessarily complicated. While Red Bull-Bora-Hansgrohe's riders use medical-grade cooling compression boots, the Ineos Grenadiers approach is more straightforward.
"We have a few devices, but there's nothing complicated at the end of the day. It's just like a tub of cold water. The same as if you're cold, the best, most proven thing to do is to get in a bath of hot water, and that helps you warm up.
"So we've gone back. You see these fancy new ice vests all the time, and the guys with ice socks and all those things, but that's more of a sensation thing actually. If you put the ice sock on your back, you're actually not gonna drop your body's temperature.
The Ineos Grenadiers team has in fact been using ice vests and ice socks both before and after the first two stages of this year's Tour, but as with most teams, the desire to bring the core temperature down before a race provides a minor performance gain, as it takes longer for the body's temperature to climb to those detrimental levels.
The average core temperature for humans is around 97°F (36.1°C) to 99°F (37.2°C). Power output can drop by 5% per degree Celcius increase (Racinais et al).
"If you can get to the race cool, that's the first thing, and then all you're actually doing is you're fighting a losing battle in overheating."
Interestingly, to an extent, Norelle disagrees with Dempster's take. She believes ice socks do aid in reducing the core temperature, but she's keen to admit it's "a little bit of both."
She explained that "a lot of the science shows that cooling around the base of your head, around your neck, is the most effective way to keep your core body temperature low," later adding that there are other techniques that 'trick' the body into feeling cooler, even if the physical effect is nonexistent.
"I think the ice, certainly shown from the research, really does help cool the core body temperature. You can do a range of tests to actually test that but then the water on the head also is just a feeling of refreshment, getting rid of sweat, but also staying cool in that way.
"Menthol is one often that people will use. It's that cool, refreshing taste in your mouth, so even though it may not change things, it gives you a mental refresher. Those are techniques that can work in that way, but we really want them as a secondary."
Once the day's racing is done, many of the teams have an ice bath inside the back of a van – as seen at Ineos Grenadiers, UAE Team Emirates and Astana Qazaqstan, to name just three – while Red Bull-Bora Hansgrohe's approach is a little more high tech.
Team manager Ralph Denk, alongside press officer Stefan Flessner, explained that the team use a cold therapy wrap system from the American brand, Game Ready. Working in a similar way to recovery compression boots, these pump cold water through the wrap to cool the body.
They can also work with warm water, but of course that would be torturous in temperatures such as these. It's primarily a medical product, and it comes in various shapes and sizes for different body parts, but the boots are used by the team, presumably for the additional benefit of compression on the riders' hardest-working muscles.
DSM's approach is more focused on hydration and a gradual return to a normal temperature, rather than shocking the body with ice or any high-tech solution. Of course, this could also be a budget constraint for the team, who don't have quite as deep pockets as the teams fighting for GC.
"There's been some research looking at pool baths, ice baths, things like that," Naumann explained. "And actually, the research shows that that's not necessarily totally effective, because it can be quite a temperature shock for the body. What we really focus on is hydration. They'll have recovery drinks and cold drinks, and then we just step through the recovery meal protocol. So after the rest, it's really about hydration, and obviously the air conditioning really, really helps as well."
