The Tour de France is a gruelling 3 week endurance event. This year (2015) the event will run from Saturday July 4th to Sunday July 26th, will be made up of 21 stages and will cover a total distance of 3,360 kilometres (2100 miles). The race will include many mountain passes and several mountain top finishes. Energy expenditure can be 2-4 times that of the average person and it can be a challenge to eat enough to maintain energy balance.
Losing weight rapidly during a Tour de France will mean early fatigue, loss of strength and endurance and could mean early elimination from the race. Therefore one of the daily challenges for the riders is to make sure that energy intake is adequate.
A few studies report energy intakes in stage races. As far as I am aware only one study reported energy expenditure and nutrition intake during the Tour de France (4). This was a study initiated by Professor Wim Saris from Maastricht University (Netherlands), who was the supervisor for my PhD. In a study published in 1989, they described energy intakes during the Tour de France and concluded that on some days it was difficult to stay in energy balance. This is partly because the riders spent a lot of time on the bike and there is less time to sit down and consume a very large meal. Energy intake on the bike was relatively small.
Energy expenditure was measured using the gold standard technique (which involves drinking so called doubly labelled water (DLW) and collecting urine samples) and averaged around 6000 kcal per day. This technique is the most accurate available but the water (DLW) is also extremely expensive.
The peak day during the Tour resulted in an energy expenditure of no less than 9000 kcal. Although these results are now more than 25 years old they are probably still accurate. The power outputs of riders may be slightly higher today, but the stages are also slightly shorter. So overall, differences are probably small.
Because these numbers don’t always mean a lot to people I like to convert them to a unit that makes it possible to visualise the challenge of eating 9000 kcal: 9000 kcal is the equivalent of 27 regular cheeseburgers.
Some other studies measured energy intake during stage races. One report from a team in the Tour of Spain suggested an average energy intake of just under 6000 kcal. In this early report only 15% of energy was consumed during the race. Of course it is not easy to eat a lot during the race but it is an opportunity for riders to take energy in.
There may be a trend towards greater intake during the stages in recent years:
We performed a study at the Tour of Spain and the Dauphine Libere to study carbohydrate intake during these races and found an average intake of 64 g of carbohydrate per hour (250 kcal). It must be said though that there were quite large individual differences with some riders ingesting 29 g/h and some 107 g/h.
The most recent study also reported energy intakes around 6000 kcal during a stage race (Tour of Andalusia: 4 days 648 km(405 miles)). In this report energy intake during the stages was 26% and thus these riders did not have to eat as much post race.
Energy intake is typically 6000kcal on average during professional stage races with peaks up to 9000kcal
Energy intake during the stages is relatively small, but there may be a trend towards greater carbohydrate intake during the stages in recent years.
García-Rovés et al. Macronutrients intake of top level cyclists during continuous competition--change in the feeding pattern Int J Sports Med 19: 61-67, 1998
Pfeiffer B, Stellingwerff T, Hodgson AB, Randell R, Pöttgen K, Res P, Jeukendrup AE. Nutritional intake and gastrointestinal problems during competitive endurance events. Med Sci Sports Exerc. 2012 Feb;44(2):344-51
Sánchez-Muñoz et al Nutritional intake and anthropometric changes of professional road cyclists during a 4-day competition. Scand J Med Sci Sports. In press 2015
Saris WH, van Erp-Baart MA, Brouns F, Westerterp KR, ten Hoor F. Study on food intake and energy expenditure during extreme sustained exercise: the Tour de France. Int J Sports Med. 1989 May;10 Suppl 1:S26-31