Publications
Partners
Chris Carmichael (File)
Chris Carmichael
Assuming of course that they didn't crash during the wet and slippery ride into Barcelona, Spain, yesterday's cooler temperatures and rain may have been a blessing in disguise for men hoping to ride well in the first summit finish today. Managing core temperature is crucial for long-term success at the Tour de France, and today's conditions make it easier for riders to keep their core temperatures in check.
The first few days of the 2009 Tour de France were extremely hot, with temperatures in the 90s and close to 100 degrees (F). Three-quarters of the energy a cyclist expends on the bike is lost - mostly as heat - and that heat has to be dissipated in order to keep core temperature at or near 98.6 degrees Fahrenheit. Yes, you read that right, three-quarters of the energy you burn while pedalling is lost, and only one-fifth to one-quarter, or 20 to 25 percent, actually moves you forward. Cyclists, even the most experienced pros, achieve about 25 percent mechanical efficiency on the bike, meaning some energy is lost to friction in the drivetrain and other areas, but mostly to heat.
Sweat is the body's primary means of cooling itself. As water evaporates off the skin, it carries heat away from the body, but when air temperatures are higher, core temperature can rise faster than the sweat-based cooling system can get rid of the heat. One of the adaptations we see with training is an increase in an athlete's sweat rate, allowing them to deliver more fluid to the skin to better keep up with the rise in core temperature. At the same time, the composition of sweat changes as athletes become more trained. A novice's sweat will generally contain more electrolytes per unit volume than an elite athlete's, because the elite athlete's body has adapted to retain the electrolytes while increasing fluid delivery to the skin.
Over the past few days, riders have been going through about three bottles of fluid per hour on the bike. That's 12 bottles in a four-hour stage, and some may have consumed more. That's on top of the fluid consumed before and after the stage, and well into the evening. But when it's 95 degrees in the south of France or near Barcelona, Spain, it's difficult to stay completely hydrated even drinking that much fluid.
A cooler and rainy day like yesterday can be a blessing for Tour de France riders because it reduces the demand for fluids. The cooler air temperatures make it easier for athletes to keep their core temperatures under control, and the rain does an even better job. Fortunately, rain in Girona or Barcelona, Spain in July is not freezing cold like it can be in the mountains. If riders get caught in the rain in the Alps, they need to be concerned that the cold rain could drop their core temperatures so low that they won't be able to perform the high-intensity efforts necessary to stay with the leaders. But yesterday in Spain, the rain was pretty comfortable and helped keep riders cool. That's part of the reason you didn't see too many riders bothering to put on rain jackets.
A cool and rainy day today may allow some riders who were starting to get behind in hydration a rare chance to catch up. By consuming a lot of fluids today, you could fully replenish what you've lost over the first several days of the Tour de France.
To understand the potential impact of yesterday's weather, think back to 2003. There was a heat wave in France that year that killed more than 10,000 people. During the Tour de France, riders were beside themselves trying to get enough fluids, and near the end of the second week, Lance Armstrong started having a dehydration crisis. No matter how much fluid he consumed, he kept losing weight. His body wasn't processing the fluids properly anymore and he was growing more and more dehydrated with each passing day. The Stage 12 individual time trial turned into a disaster. Between the morning and the end of the stage Lance lost something like 6 kilograms of water weight, and he lost 1:36 to German rival Jan Ullrich as well. Lance retained the yellow jersey, but only by 15 seconds.
The following day, Ullrich should have been able to take advantage of Lance's weakened state and taken the yellow jersey. He distanced himself from Armstrong in the final two kilometres of a summit finish and with a time bonus brought the gap to the yellow jersey down to 15 seconds. But by the time the race reached Stage 15, the weather had broken and the temperatures had cooled. Despite a crash on the final climb, Lance reached the finish atop Luz Ardiden first and extended his lead back to 45 seconds. By the end of the 2003 Tour, Lance would win by 1:06 over Ullrich.
The heat in 2003 put Lance in a dehydration crisis, and a change in the weather helped him get back on terms with his fluid intake. A similar scenario could be playing out right now for riders in the 2009 Tour de France. We haven't seen anyone crack because of the heat yet, but that's because we're only six stages into the race. However, there may be riders who started Stage 6 in a pretty desperate condition in terms of hydration, and yesterday's cooler temperatures and rain may have helped them take a step back from the brink of disaster. Today is the first mountain stage of the Tour, and yesterday's weather may help some of the climbers and yellow jersey contenders have good legs in Stage 7. Either way, it's likely that at least one yellow jersey contender will lose enough time on tomorrow's summit finish to significantly diminish his chances of winning. I don't know who it will be, but the first major mountain climb pretty much always weeds out at least one pre-race favourite.
Source: www.bicycling.co.za
Chris Carmichael has been Lance Armstrong's coach for 20 years and is the founder of Carmichael Training Systems (CTS).
Assuming of course that they didn't crash during the wet and slippery ride into Barcelona, Spain, yesterday's cooler temperatures and rain may have been a blessing in disguise for men hoping to ride well in the first summit finish today. Managing core temperature is crucial for long-term success at the Tour de France, and today's conditions make it easier for riders to keep their core temperatures in check.
The first few days of the 2009 Tour de France were extremely hot, with temperatures in the 90s and close to 100 degrees (F). Three-quarters of the energy a cyclist expends on the bike is lost - mostly as heat - and that heat has to be dissipated in order to keep core temperature at or near 98.6 degrees Fahrenheit. Yes, you read that right, three-quarters of the energy you burn while pedalling is lost, and only one-fifth to one-quarter, or 20 to 25 percent, actually moves you forward. Cyclists, even the most experienced pros, achieve about 25 percent mechanical efficiency on the bike, meaning some energy is lost to friction in the drivetrain and other areas, but mostly to heat.
Sweat is the body's primary means of cooling itself. As water evaporates off the skin, it carries heat away from the body, but when air temperatures are higher, core temperature can rise faster than the sweat-based cooling system can get rid of the heat. One of the adaptations we see with training is an increase in an athlete's sweat rate, allowing them to deliver more fluid to the skin to better keep up with the rise in core temperature. At the same time, the composition of sweat changes as athletes become more trained. A novice's sweat will generally contain more electrolytes per unit volume than an elite athlete's, because the elite athlete's body has adapted to retain the electrolytes while increasing fluid delivery to the skin.
Over the past few days, riders have been going through about three bottles of fluid per hour on the bike. That's 12 bottles in a four-hour stage, and some may have consumed more. That's on top of the fluid consumed before and after the stage, and well into the evening. But when it's 95 degrees in the south of France or near Barcelona, Spain, it's difficult to stay completely hydrated even drinking that much fluid.
A cooler and rainy day like yesterday can be a blessing for Tour de France riders because it reduces the demand for fluids. The cooler air temperatures make it easier for athletes to keep their core temperatures under control, and the rain does an even better job. Fortunately, rain in Girona or Barcelona, Spain in July is not freezing cold like it can be in the mountains. If riders get caught in the rain in the Alps, they need to be concerned that the cold rain could drop their core temperatures so low that they won't be able to perform the high-intensity efforts necessary to stay with the leaders. But yesterday in Spain, the rain was pretty comfortable and helped keep riders cool. That's part of the reason you didn't see too many riders bothering to put on rain jackets.
A cool and rainy day today may allow some riders who were starting to get behind in hydration a rare chance to catch up. By consuming a lot of fluids today, you could fully replenish what you've lost over the first several days of the Tour de France.
To understand the potential impact of yesterday's weather, think back to 2003. There was a heat wave in France that year that killed more than 10,000 people. During the Tour de France, riders were beside themselves trying to get enough fluids, and near the end of the second week, Lance Armstrong started having a dehydration crisis. No matter how much fluid he consumed, he kept losing weight. His body wasn't processing the fluids properly anymore and he was growing more and more dehydrated with each passing day. The Stage 12 individual time trial turned into a disaster. Between the morning and the end of the stage Lance lost something like 6 kilograms of water weight, and he lost 1:36 to German rival Jan Ullrich as well. Lance retained the yellow jersey, but only by 15 seconds.
The following day, Ullrich should have been able to take advantage of Lance's weakened state and taken the yellow jersey. He distanced himself from Armstrong in the final two kilometres of a summit finish and with a time bonus brought the gap to the yellow jersey down to 15 seconds. But by the time the race reached Stage 15, the weather had broken and the temperatures had cooled. Despite a crash on the final climb, Lance reached the finish atop Luz Ardiden first and extended his lead back to 45 seconds. By the end of the 2003 Tour, Lance would win by 1:06 over Ullrich.
The heat in 2003 put Lance in a dehydration crisis, and a change in the weather helped him get back on terms with his fluid intake. A similar scenario could be playing out right now for riders in the 2009 Tour de France. We haven't seen anyone crack because of the heat yet, but that's because we're only six stages into the race. However, there may be riders who started Stage 6 in a pretty desperate condition in terms of hydration, and yesterday's cooler temperatures and rain may have helped them take a step back from the brink of disaster. Today is the first mountain stage of the Tour, and yesterday's weather may help some of the climbers and yellow jersey contenders have good legs in Stage 7. Either way, it's likely that at least one yellow jersey contender will lose enough time on tomorrow's summit finish to significantly diminish his chances of winning. I don't know who it will be, but the first major mountain climb pretty much always weeds out at least one pre-race favourite.
Source: www.bicycling.co.za
Chris Carmichael has been Lance Armstrong's coach for 20 years and is the founder of Carmichael Training Systems (CTS).
