105 Years of Cycling Science from the Tour de France

By Coach Fred Matheny

Conrad Earnest, Ph.D., is an exercise scientist from the Pennington Biomedical Research Center in Baton Rouge, Louisiana. He reviewed the history of the Tour de France, along with the history of exercise physiology, showing how cycling’s greatest race provided a catalyst for research.

Earnest detailed studies done during almost a decade on the Banesto team’s riders (primarily in the 1990s). He was also interested in how the Tour has changed in more than 100 years in areas such as physiology, nutrition and the bicycle itself.

The Early Days: A Real Hard Man’s Tour

In the 1890s, boxing and cycling were the two most popular sports in Europe. Cycling took place on wooden tracks in enclosed arenas so riders made maximum efforts in air blue with tobacco smoke. No one complained, however. Smoking was thought to open the lungs and aid in breathing. Road racing wasn’t as popular so the Tour de France was a daring innovation.

The first Tour was in 1903 in a world much different from the present day. Roads were generally unpaved or surfaced in bumpy cobblestones. Bicycles had one gear and weighed 30 pounds or more. Sports nutrition and hydration were unknown. Same for Lycra, carbon fiber or plastic water bottles. Aluminum wasn’t used in components. Even things we take for granted, like chains, were primitive.

The Tour was unrecognizable as well. The inaugural edition covered 2,500 kilometers (1,550 miles) — in only 6 stages! These monster stages usually began at 2 or 3 a.m. Riders slogged over gravel roads for hours on their heavy single-speed bikes. Cheating was rampant in those days. Riders were disqualified for hitching rides on trains.

Mechanical support was forbidden so competitors had to fix their broken bicycles themselves. In 1913, Eugene Christophe famously had to weld his broken fork at a village blacksmith’s shop. Then he was penalized 10 minutes because he’d allowed a young boy to work the bellows.

The Birth of Exercise Physiology

The toll on the human body was extreme in the early Tours. The new-fangled bicycle had transformed travel, allowing fit riders to cover long distances at the unheard of average speed of 15 mph (24 kph). Since the dawn of history it had been a 3-miles-per-hour world and most northern Europeans worked the soil, rarely traveling more than a few miles from their birth place. Train tickets were expensive and trains didn’t run everywhere villagers might want to go. Suddenly, thanks to the bicycle, human-powered speed more than quadrupled.

Society lionized riders who could suffer like their laboring forebears while skimming along the roads at frightening speeds. Fans wanted to see stoic fortitude in the face of rain, mud, saddle sores, frequent punctures and inhumanly long stages. Cycling attracted poor, uneducated riders who would have been laboring in fields or factories if not for the new sport. So the physical demands were extraordinary. The 1926 edition of the Tour covered 5,700 km (3,534 miles) compared to the 3,550 km (2,200 miles) of a typical race today.

As a result, science became interested in how the body adapted to the brutal stresses of 400-km (248-mile) stages. The Tour was instrumental in arousing interest in ‘work physiology,’ a field that we now call exercise physiology. Earnest showed slides from the 1920s of study subjects who pushed wheelbarrows on elevated treadmills. One pictured the first heart rate monitor — a 75-pound (34-kilo) backpack — worn by a fellow on a stationary bike. He did not look happy.

The Tour has shown us that human physiology hasn’t changed in the last century. Riders struggling up alpine climbs in the Roaring ’20s were working with the same engine as today’s riders, although modern cyclists hone their ability through specialized training, sleeping at altitude and analyzing data from power meters.

Into the Mountains

The first mountain stage took place in 1905 with the ascent of the Ballon d’Alsace, 9 kilometers at 7-9%. It was unpaved, there were no team tactics, and the heavy bikes had only one gear. The winner, Rene Pottier, averaged 12.5 mph (20.1 kph). Current calculations show that he generated 370-390 watts on the ascent, or 5.8 watts per kilogram of body weight.

Here are some modern comparisons: The Banesto team averaged 370 watts in lab studies of their lactate thresholds — about the intensity they could hold for the duration of the Ballon d’Alsace climb. (Some produced higher power numbers. Some lower.)

We need to remember that those early bike racers weren’t professional athletes. Most of them worked full time when they weren’t racing. They didn’t know about nutrition or hydration. They rarely trained as we would use the term but rather got into shape by racing. If the pioneer racers had had access to modern methods, we’d expect their results to be similar.

Interestingly, a rider named Anton Magnin used altitude training in 1931. Now riders employ the “train low, sleep high” technique all the time. They do their workouts at low elevation where greater air density means they can train extremely hard. Then they sleep at higher elevations to stimulate production of red blood cells. Often, altitude tents are used to make this process more practical than actually living in the mountains, something that Magnin and his fellow riders couldn’t imagine.

Mechanical Advantages

Derailleurs weren’t introduced into the Tour de France until 1937. Tourists had used sophisticated gearing systems for years but racers were afraid that the chain’s convoluted route added too much friction into the system. The relatively primitive chains of the era weren’t as flexible as modern chains so this was a legitimate worry.

Eventually it became evident that derailleurs and lower gears enabled a racer to climb much more effectively due to a higher cadence. Earnest discussed studies showing that oxygen consumption is higher at cadences below 80 rpm. In addition, blood flow may be impeded at low cadences because of the hard squeeze of the muscles on the downstroke. At higher cadences the muscles aren’t tensed as long so blood is free to flow through the legs.

Nutrition and Recovery

From the first Tour it was evident that the event took a major toll on the bodies of racers. There was no team support in the early years so they stopped to get food and drink from cafes along the route. The Banesto studies show that modern racers need 4,000-8,000 calories per day for the 21 days of the Tour. They also need 6-7 liters of fluid just to maintain hydration. Finding enough food and fluids, while under racing pressure, was extremely difficult for Tour riders during the classic age so they ate and drank whatever they could find. Wine and beer were extremely popular.

Although modern stages are shorter, the pace is faster so the toll on racers hasn’t lessened. A recent study of middle-of-the-pack finishers in the Tour showed that they had the heart rate variability of congestive heart failure patients. That is, as the Tour went on their heart rates didn’t vary much from rest to all-out effort. When the Tour started they might have had a resting heart rate of 50 bpm and a maximum heart rate of 190, but after 3 weeks of racing their resting heart rates increased to 65 and their maximum heart rates decreased to 160. They “just couldn’t get their heart rates up” — a feeling familiar to any overtrained cyclist. However, no permanent damage was done. The Banesto riders recovered incredibly fast after the Tour.

Some studies have looked at what happens when a Tour rider is injured in a crash. Earnest calls this “the fatal cycle.” Healing road rash and contusions requires the body to use energy that otherwise would go to pedaling. So not only do crashed cyclists have to contend with the discomfort of their injuries, they also have less energy available to meet the demands of the race. During the first couple of days post-injury, the rider’s reserves become rapidly depleted and performance declines. Often there is no point in continuing.

Talent Is Always the Key

What does it take to be competitive in the Tour de France?

Earnest says a rider needs a VO2 max of 70-80 ml/kg/min, although maximal oxygen uptake isn’t as predictive of success as wattage. A modern Tour de France rider weighing around 154 pounds (70 kg) should be able to reach 500 watts on a ramped exercise test and have an aerobic threshold of 400 watts. If we look at the history of the Tour, those numbers haven’t changed appreciably since 1903.