Expert view: How to fuel for a time trial?

The men's 2025 Tour de France is set to have two time trials: today’s 33km challenge around Caen, and stage 13, a shorter but tougher effort in the Pyrenees, across a distance of just 10.9km.

This year the women’s Tour de France Femmes does not feature an individual time trial, but we can apply similar concepts to both the male and female preparation, of course, with some personalisation.

Broadly speaking, an individual time trial is a race against the clock – just you and your bike. Riders start in ascending order according to their GC placement and compete on specialised time trial bikes designed for optimising aerodynamics, as they aim to complete the event's length in the shortest possible time frame. The use of specialised equipment ranges from disc wheels, aerodynamic suits, helmets and shoe covers and extends to off the bike nutrition and specific supplement resources. 

So when it comes to nutrition, how might a professional athlete approach a time trial, and how does this differ to their approach to a standard road race? The first major difference between a time trial and a road stage is the length and intensity of the effort. A regular road race can range anywhere from 3-6 hours (sometimes more), with changes in pace and intensity occurring throughout the race depending on the parcours and the race situation. Road races of this length require a lot more on-bike fuelling strategies and hydration to ensure riders maintain focus and energy when required to perform. Compare this to a time trial where you can expect your effort to be over in less than an hour, giving riders next to no time to consume any food or hydration while on the bike, meaning pre-race strategies are king. 

The moment the riders completed stage 4, they were thinking of their pre-race for stage 5. This immediately involved recovery in terms of protein and carbohydrate intake, which is a normal process following all stages, as well as focus on hydration depending on the stage and the individual. Many teams will optimise hydration, salt and electrolyte replenishment from pre-season testing, and riders will follow these guidelines.

In both time trial stages, the first rider will roll down the start ramp at 13:10 CET. Many riders will work backwards from this, to time their pre-race meals. Again, this concept is typically applied to road races as well. A general rule of thumb is to consume the last ‘main’ meal three hours prior to a race, so riders may try and eat a later breakfast at 10:00am, prioritising rest in the morning. They may also split this if they prefer an earlier breakfast, but this three-hour window is quite important for digestion. Riders will not want to start a race feeling empty, but also not ‘heavy’ from too much food. 

This is where we start to separate a time trial from a road race, with specific supplements taken on to help with maximum performance against the clock. Such supplements can include IOC-approved supplements like caffeine, bicarbonate and beta alanine, to name a few. Other IOC supplements such as creatine and nitrates can be effective but require more chronic (prolonged) loading (intake) periods to gain the most significant advantage. 

These supplements have the combined benefits of energy stimulants and enhanced focus, as well as lactate blocker and hydrogen buffer. Why do these matter? Well, a time trial means sitting, for a large majority of the time, on or above threshold. Your threshold is determined by calculating your sustainable power output – that is, what power you can maintain for an extended period – which means you need to be aerobic and remove the by-products your body is producing at a quicker rate than they accumulate. Otherwise, your muscles will essentially be unable to operate as they experience a build-up. You know how we talk about lactate build-up? If we have buffers in the mix, they are essentially assisting to clean up that by-product, or make it more tolerable for a period of time, by altering vital internal levels to help maintain balance as by-products accumulate. Thus allowing you to dig deeper or maintain a higher effort while using it. 

Bicarbonate focuses on the pH levels, as hydrogen ions build up from intense exercise. Bicarbonate picks these up and maintains an alkaline environment in the muscles and blood. 

Don’t be fooled into thinking all of these factors will make you win a Tour de France time trial. Of course, it’s all the approaches working together to get the best out of an athlete. A dehydrated cyclist won’t get much benefit from a bicarb protocol, just as an under-fuelled athlete probably can’t make up for it on the start line. 

Not every supplement suits every athlete. Some riders don’t like the impact of caffeine, experiencing side effects such as anxiety, jitters, disrupted sleep, or increase urination which can impact hydration levels, while others don’t like bicarbonate, which can cause gastrointestinal upset, bloating, gas or increased thirst. 

Almost all athletes will have trialled and tested these approaches in training and practice events in the lead-up  to these events under the guidance of their nutritionist or dietician and determined their race plan based on the best fit for their individual needs. 

As soon as riders finish their time trial, it’s now time to start preparing for stage 6, a hilly, 201km stage. So, expect to see riders taking on quick carbohydrates like a Fanta or Coke for sugars and hydration, nitrates to reduce fatigue, protein for muscle recovery and likely taking on a meal once in the bus and cleaned up. 

And then, we go again tomorrow.