Nowhere is the necessity of an efficient fuel energy system in an endurance sport more evident than with the cyclists in the Tour de France who ride up to 180km per stage for 21 stages (with only one day of rest) often through some of the most challenging terrains in the world. The Pyrenees, the Alps – mountain roads just don’t get any tougher or higher. At rest, the caloric energy required for a 75kg man to sustain life is somewhere in the neighbourhood of 1500-2000 calories. Taking into consideration that cycling is a highly efficient sporting activity with respect to moving a body, Tour cyclists use up 25-30 calories per km (0.3-0.4 calories per km per kg of body mass) – this translates to an average of over 4000 calories per day at a minimum. That’s a total of more than 5500 calories of energy input per day just to physically survive a stage in the Tour (some cyclists have been known to eat as many as 9000 calories per day!)

To prevent hypoglycemia (low glycogen) otherwise known as the dreaded “bonk”, Tour rules do permit cyclists to eat from food bags during the race, otherwise there just would not be enough waking hours in the day for the cyclists to consume all these calories. Since eating cheeseburgers or chocolate bars all day is not practical, the science of feeding a Tour cyclist is mandatory. Breakfast, three to four hours prior to the starting time, will include highly digestible carbohydrates such as cereal, rice and pasta. A few hours before a stage start, cyclists will consume a slow-release carbohydrate liquid mix bringing their pre-race caloric count to 1000. While burning up to 900 calories an hour, they can only still process approximately 300 calories per hour. Throughout the ride cyclists must stay hydrated and will also consume a few boxes of fast energy bars and gels, while Panini’s are popular for lunch while still on the bike as they provide sustenance. Post race recovery drinks and containers of white rice and egg dishes provide proteins necessary to quicken muscle repair, followed by a balanced dinner binge that not only aids in full muscle glycogen recovery but starts loading for the energy system for the next day.

For more information on fueling to feed the endurance athlete, please visit SIRC.