Have I finally found out why I keep getting dropped? Why hydration is more important than you think for cycling performance

Hydration might not be the most glamorous topic in cycling, but it has the potential to make a far bigger difference to your on-bike performance than just about anything else. 

It's no wonder, then, that pro teams are spending a huge amount of resources perfecting their hydration strategies. With the help of a Tour de France stage winner or two, a heat chamber and some hydration boffins, we wanted to see what these strategies look like and take the plunge into the world of sodium and beyond...

When it comes to going faster on the bike, you might be looking for things that you can copy off the pros… but I'd hazard a guess that you've overlooked hydration. That might just be a bad move, because according to the likes of Jan Bakelants and Victor Campenaerts, it’s potentially made a bigger difference to their performances than literally anything else. 

Forget waxed chains, forget disc brakes, forget aero... here we’re talking about proper hydration. It sounds simple, but it’s a topic that has often been ignored - even by the pro peloton - for years. On endurance rides, staying hydrated and hydrating properly can make a far bigger difference than any of the bike modifications listed above. In fact, many accredit modern fuelling and hydration for the step change in speed that the pros are now riding at.

So, just how do you know if you're hydrating properly, and has the answer to unlocking our full potential on the bike been staring us in the face all along?

The three things you need to perform

When we talk about hydration, we don’t just mean downing a few bottles of water/ Whether you're riding hard, easy, in the hot or in the cold, chances are you are to some degree sweating. After all, this is one of the things that makes us humans so good at endurance events. 

To find out what we should be putting into our bodies to replace whatever we’re burning and sweating out, we got in touch with the CEO of Precision Fuel and Hydration, Andy Blow, who explained that it’s more simple than you might think. 

Blow was able to tell us that there are three 'levers' to your nutrition performance, and to perform at 100% of your ability you need:

• Carbohydrates
• Fluids
• Electrolytes

Blow explained that while many pros and amateurs alike have focused on the carbohydrate pillar - and to some extent fluids - electrolyte consumption is often overlooked.

Does it matter as an amateur?

Here in the UK, we're not very often exposed to 40-degree heat and real killer climbs, so it could be assumed that we don't need to worry about replacing electrolytes.

To an extent, this is true. According to Andy Blow, the average demands of an amateur cyclist is "not likely to be as high as professionals at the top of their game on the hottest days, but they're not inconsequential."

"You need to be aware of your individual needs and losses," he adds. 

Blow also explained that "most of us can bluff it for a few hours if it's cool, [riders] get used to accepting a level of degradation in performance thinking that it's normal."

So, yes, if you're an amateur who cares about performance or just feeling good at the end of long rides, then you should be looking at carbohydrate, fluid and electrolyte intake.

How salty are you?

Precision Fuel and Hydration were keen to get across that simply drinking more is not the answer to all our hydration woes. In fact, if you take on more sodium than your body needs you could see some quite catastrophic results.

Too much sodium could see you gain weight due to water retention, see an increase in your blood pressure and elevated your core body temperature, leading to accelerated fatigue; and that’s before we even get into what it could do to your bowels! (kudos if you get the reference to the picture below). 

For this reason, the vast majority of hydration products on the market verge on the side of caution, or at the very least cater to the average sweater.

Sweat is not created equal though. My sweat is different to Andy’s sweat, which is different to Jan Bakelaants’ sweat, and all of them are probably different to your sweat. 

Emily Arrell, a Sports Scientist at Precision Fuel and Hydration, explained that the sodium concentration of sweat can vary from anything between about 300mg/L, to over 2,000mg/L. If you're one of these salty sweaters near the top of that range, then it's fairly self-explanatory that you'll need to replace more.

It turns out that I lose 1,208mg of sodium per litre of sweat, making me a "salty sweater". This might explain why I often struggle in hot conditions, even when I think I've fuelled properly! Jan Bakelants and Victor Campanaerts are less salty, with values of 1,044mg/L and 957mg/L respectively.

Looking at those values, you might think that it's possible to train your body to have less salty sweat. Unfortunately that's not the case. 

Arrell explained that the salt content of your sweat is almost completely genetic, and over the last 10 years of testing the pros, values have fluctuated by less than 10%. It looks like I’m stuck with my salty sweat then.

Tell-tale signs of having salty sweat - other than feeling bad at the end of long rides - are cramping, white marks on your kit, stinging eyes, craving salty foods and the sweat's taste (you probably don't want to taste your sweat, but the saltier it is, the saltier you are). 

How sweaty are you?

Before working out how much salt we need to replace, we need to work out how much sweat is being expelled, as this too varies from person to person. As we mentioned earlier, sweating is a very effective way of cooling the body, and pro endurance athletes tend to have pretty high sweat rates.

To find out mine I went head-to-head with Jan Bakelants - a Tour de France stage winner - in a heat chamber. There's something you don't get to do every day! 

The heat chamber was set to 40 degrees centigrade, and we started off at 40% humidity. Bakelants explained to us that not all heat is created equal; for example, even the hottest Tour de France stages are relatively easy to manage in comparison to more humid climates such as the 2016 Olympic Games in Rio.

I soon got a taste of what he meant. 40 degrees and 40% humidity was certainly uncomfortably warm to be doing a turbo session in, but nothing compared to how I started bucketing sweat as the humidity was increased to 70%.

After a weigh-in it was calculated that I was losing sweat at a rate of a whopping 2.03kg per hour. Just to put that into context, that’s around 2.7% of my body weight each hour. Admittedly I won’t always be sweating as profusely as I was in the heat chamber, but if I was and didn't replace any of that salt, then I’d be in serious trouble in under an hour while not even pushing that hard. 

I’ve done some research, and at 1% dehydration - or after about 20 minutes in the heat chamber - my core body temperature will already be elevated. That means I'm fatiguing quicker than I otherwise would.

At 2% dehydration (after about 45 minutes) I’m going to see a drastic reduction in my already questionable athletic performance. As Bakelants and Campanaerts explained: unless you’re Pogacar, that means you’re getting dropped.

Keep going and at 5% I’m approaching heat exhaustion. At 7% I’ll probably start hallucinating, and at 10% things are looking particularly un-rosy with something called circulatory collapse.

What can we do about it?

Now that I know my sweat rate and my sweat saltiness, I can work out how much I need to replace. The experts reckon that if I were to ride Stage 18 of this year’s Tour de France, the one that Campanaerts won, then I’d need to be consuming about 1000mg of sodium for every litre of fluid lost, and that I need to be drinking at least one bottle per hour.

Before doing this testing, I must admit I would have probably have just focussed on my carbohydrate intake for a long ride, and realistically that means that I’d be getting less than half the sodium that I need to perform at my best. Now, you might not need the same amount of sodium as me, but there are a high percentage of riders that will be in the same position as me, and therefore riding at less than 100% of their ability.

To summarise... 

Andy Blow wrapped up the day by adding: "We spoke to Jan Baklenats earlier who found out in his career he couldn't perform in the heat for many, many years. He got sweat tested, he understood his sodium losses and started to correct for that, and described it as binary. It unlocked his performance, it was a 0 or 1 proposition.

"You have a level of performance that you can unlock which is based on your fitness. We call that 100%, and if you don't hydrate you're going to be down below that.

"Anything that can get you above that, to 103% or 110% say, is usually banned or illegal, but getting your hydration and fuelling right enables you to express your maximum athletic potential.

"Do it consistently [and] as a professional that's now a necessity. As an amateur, that means that you're going to stand more chance of beating your rivals."

Let us know in the comments section below whether you think you’re a salty sweater, and what you do to stay hydrated on the bike...