Cycling is an energy-consuming sport that requires continuous filling of energy reserves. Only a properly fueled body can sustain long-lasting efforts typical for this sport.
Professional cyclists are energy-consumption-wise in a category of their own. Their races and training sessions are longer and harder than what an average cyclist is used to. On top of that, they also ride much faster, which reflects in the amount of calories burned.
Energy consumption at Tour de France
Total calorie consumption is the greatest at the longest races. The more stages there are, the bigger the overall number of calories burned.
Tour de France consists of 21 stages, all of which are very different from each other. Flat stages are the easiest, a bit tougher are hilly stages, while mountain stages push cyclists to their limit. The calorie consumption varies heavily based on stage difficulty.
Flat stages are calorie-wise the most modest of them all. On average, cyclists burn 4,000 kcal during a flat stage. The value can vary based on stage length, the number of vertical meters, and the possible presence of wind, which can turn an easy stage into a hellish one.
On a difficulty scale, flat stages are followed by hilly stages. Hilly stages can differ noticeably. Some barely justify the title and can almost be placed among flat stages, while others border on mountain stages.
Consequently, the calorie consumption on hilly stages varies considerably. On easier profiles, it's around 4,000 kcal, while the toughest stages force cyclists to burn up to 6,000 kcal.
Then there are mountain stages. By far the most spectacular for viewers, but also by far the most challenging for cyclists. It's typical for queen stages to contain around 4,500 meters of climbing, which takes its energy toll. This amounts to about 7,000 kcal.
On average, cyclists on the world's biggest race burn 5,000 kcal per stage. If we multiply this number by the number of stages, we get 105,000 burned calories in the span of three weeks.
For comparison, we can mention that an average person burns 2,500 to 3,000 kcal per day. So, in just five hours, which is usually how long a stage lasts, cyclists burn twice as much energy as the daily average.
It probably goes without saying that cyclists have to constantly replace all the energy they lose during the race. This can be done in many ways – from energy gels and bars to energy drinks.
Energy consumption at one-day classics
One-day classics have similar energy requirements to the toughest mountain stages in multi-day races.
Still, there are a few differences between classics and mountain stages in multi-day races. One-day classics are much longer. In most of them, cyclists cover well over 200 kilometers. The difference is also in the terrain, as (especially spring) classics also take place on cobblestones, which are much harder and energy-intensive to ride.
Simply by looking at the expression on the cyclists' faces at end of the race, you can tell classics take a huge energy toll.
So how much energy do cyclists actually burn?
On five largest one-day races – so-called monuments – cyclists burn 6,000 kcal on average.
The routes of one-day stages differ quite a lot. Some have more kilometers, some more vertical meters, and others have cobbled sectors. But for most parts, the differences cancel each other out and the final amount of total calories burned is pretty similar.
However, there are significant differences in energy consumption between different versions of the same race.
In 2021 Paris-Roubaix took place in the rain for the first time in 16 years. The course turned into a mud bath, which forced the riders to expend even more energy. On average, they burned 7,145 kcal, which is 1,000 kcal more than in 2019 when the race was dry.
How many calories do cyclists take in during a race?
Cyclists fill up their energy reserves before the race, but those can't last the whole duration of the race. So, they need to constantly fuel their body and make sure they don't run out of energy.
During the race, cyclists take in between 400 and 500 kcal per hour. It might seem like an easy job, but the truth is that many riders struggle to keep up with the fueling schedule during the race.
If we translate the numbers into something more tangible. Each hour, cyclists have to eat one or two energy gels (88 kcal) and one energy bar (178 kcal). On top of that, they have to drink at least 500 ml of a carbohydrate drink (177 kcal).
When we calculate all the numbers above, it becomes clear that cyclists burn more calories than they consume. That's why filling up energy reserves (glycogen stores) before the race is crucial, as they almost completely deplete on the way to the finish line.
It's also essential to refill them after the race and thus allow your body to recover. Only this way can a cyclist count on successfully completing all 21 stages of Tour de France.