Tag Archives: sports performance

Sports physiology in the Tour de France

This week marks the start of the 2019 Tour de France. This year the race covers 2100 miles in 21 days of racing, comprised of team and individual time trials as well as stages through the cities, countryside, and mountains of France, after beginning in Belgium. The Tour de France is interesting to me because it provides an excellent opportunity for a short lesson in sports physiology. This is the topic of my Health & Fitness column in the Aiken Standard this week.

Tour de France


All the riders in the Tour are exceptionally fit since their bodies have adapted to years of dedicated, intense training. Endurance sports like cycling are dependent on the delivery of oxygenated blood to the muscle to produce ATP, the energy needed to sustain exercise. The riders have large, strong hearts, resulting in the ejection of more blood to the muscle. Within the muscle there is an increase in the number of capillaries, the small blood vessels that deliver blood to the muscle, and mitochondria, the part of the cell that produces most of the ATP. Together, these adaptations allow the muscle to produce more ATP without fatigue, allowing the athlete to exercise at a higher intensity for a longer time.

But training isn’t the only reason these athletes can sustain such intense exercise for so long. Proper nutrition, especially what the athletes eat and drink before, during, and after each stage, also plays an important role. Intense endurance exercise like cycling relies on carbohydrates, in particular, muscle glycogen, as a fuel. Muscle glycogen is a storage form of glucose, sugar that the muscle converts into energy. During prolonged exercise that lasts several hours, muscle glycogen levels can be severely depleted.

Eating carbohydrates before exercise can boost muscle glycogen levels, so cyclists eat carbohydrate-rich foods for breakfast before each stage. They also consume carbohydrates in the form of sports drinks (think Gatorade) and energy bars prior to starting. In fact, they start replenishing their muscle glycogen immediately after finishing the previous day’s ride. This usually begins with a recovery beverage, which may contain some protein for more rapid muscle glycogen synthesis, and extends through carbohydrate-rich meals and snacksthat afternoon and evening.

During exercise it is crucial to maintain adequate blood glucose levels, which tend to drop since the muscle is using so much as a fuel. Failure to replenish blood glucose results in what cyclists call “hitting the wall” or “bonking,” which is like your car running out of gas. To prevent this, glucose must be replenished, typically with sports drinks, energy bars, or a sugary mixture called goo.

Prolonged, intense exercise, especially in the heat, results in a high sweat rate which can lead to dehydration. Sweat loss of several liters per hour is not uncommon during cycling, so fluid intake is essential. This means that cyclists spend a lot of time drinking water while they ride. Sports drinks are also commonly used since they contain carbohydrates and electrolytes in addition to water.

Endurance events like cycling, especially multi-stage events like the Tour de France, highlight important concepts of sports physiology. Even though you may never compete at that level, understanding how training can improve your endurance is relevant if you cycle—or run, walk, or swim—for exercise. Knowing how proper nutrition before, during, and after exercise can improve performance can help you make better decision about what to eat. Hopefully, it also gives you a greater appreciation for the science that goes into a performance like the Tour de France.


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Skip the smoothie, have a burger? Fast food for exercise recovery.

Many athletes use specialized supplements before, during, and after exercise to improve performance and enhance strength and endurance gains from training. Many non-athletes also use similar supplements, even though they may not need them. And a recent study suggests that fast food, literally meals from McDonald’s, can work as well as more expensive sports supplements for promoting muscle recovery following intense exercise. I try to make sense of all of this in my Health & Fitness column in the Aiken Standard this week.



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After exercise, many athletes consume specialized beverages and foods that supply nutrients to help their muscles recover. These recovery drinks generally contain some combination of carbohydrates (sugar) and protein and come in liquid, shake, or smoothie form. There are also energy bars specifically formulated for use after exercise. Research shows that these carbohydrate-protein recovery drinks and foods enhance muscle recovery and adaptations to training in some athletes. Even if you aren’t an athlete, you may consume these products after you work out. Let’s explore when and for whom these recovery products might be useful.

Intense endurance exercise—think of a distance runner, cyclist, or triathlete—uses muscle glycogen as a fuel. Muscle glycogen is a storage form of glucose, sugar that the muscle converts into energy. During prolonged exercise sessions that last at least 60–90 minutes, muscle glycogen levels can be severely depleted. Resynthesizing that muscle glycogen is a priority following exercise.

Athletes who are engaging in intense resistance training to build muscle and strength may also benefit from a recovery drink. Weight training stimulates protein synthesis in the muscle, so it makes sense that consuming additional protein would be beneficial. As new muscle protein is formed, both strength and muscle size are increased.

It has also been shown that combining the carbohydrates with protein results in more rapid muscle glycogen replenishment and increases muscle protein synthesis. This is why many specialized recovery drinks and foods include a combination of carbohydrates and protein. The best time to consume carbohydrates to restore muscle glycogen levels is immediately following exercise. Similarly, the muscle is most responsive to extra protein immediately after a resistance training session.

Perhaps these recovery drinks, bars, and shakes aren’t even necessary. Sports nutritionists have long recommended conventional foods and beverages for athletes after exercise. Research shows that chocolate milk is just as effective as more expensive supplements for replenishing muscle glycogen and promoting muscle protein synthesis. Remarkably, according to a study published last week, fast food may work just as well!

In this study cyclists were fed either commercial recovery aids or food from McDonald’s including pancakes, sausage, juice, a burger, fries, and soda after they completed an intense exercise session. Importantly, the meals contained equal amount of calories and nutrients. It turns out that there was no significant difference in how quickly muscle glycogen was replenished or in performance in a subsequent exercise bout between the two conditions. While the authors don’t recommend eating more fast food, this study suggests that foods not typically thought of as sports nutrition products can be effective for muscle recovery following vigorous exercise.

But what about people who engage in regular exercise to improve fitness or lose weight? The benefits of recovery drinks in athletes exist because the intense training causes changes in the muscle that allow the extra carbohydrates and protein to have a positive effect. Training at a lower intensity is unlikely to create this stimulus in the muscle, so these nutrients would not have a significant benefit. Simply put, most people don’t train hard enough to need a recovery drink.

The bottom line is that these recovery aids are not always necessary and you can get the same benefits from regular food. Something else to keep in mind is that these supplements, especially in shake or smoothie form, can be high in calories. It is entirely possible to consume more calories in a recovery beverage than you burn during exercise. This could diminish the effect of exercise on weight loss and may actually lead to weight gain. For most of us, a sensible diet with regular exercise is the key to meeting fitness and weight loss goals.

Sports Science at the Winter Olympics

So, the 2014 Winter Olympics wrapped up with the closing ceremony yesterday. If you have been watching the Olympics you have seen some incredible performances. The competitors are among the fittest and most highly trained athletes in the world, both in terms of laboratory measures of fitness and in subjective evaluations of skill. Competing in the Olympics requires years of focused, intense training and some good luck.

In my Health & Fitness column in the Aiken Standard this week I take a look at the  physiology that goes in to training for and competing in the Olympics.

First, let’s look at the fitness. This is most evident in the endurance events like cross-country skiing and speed skating. The key to performance in long-duration events like these is for the muscle to contract repeatedly and forcefully without fatigue. In order to do so, the muscle must have a steady supply of oxygen and nutrients. These nutrients are delivered through the blood, which is pumped to the muscle by the heart. The muscle takes up and uses these nutrients to produce ATP, the form of energy used by the muscle.

After months and years of endurance training the heart gets bigger resulting in the ejection of more blood to the muscle. Within the muscle there is an increase in the number of capillaries, the small blood vessels that deliver blood to the muscle, and mitochondria, the part of the cell that produces most of the ATP. Together, these adaptations allow the muscle to produce more ATP without fatigue, allowing the athlete to sustain a higher intensity (skiing speed, for example) for a longer time without fatigue.

How fit are these athletes? In the laboratory we measure VO2max, the maximal rate at which oxygen can be used by the muscle to power exercise, during intense exercise. While we don’t have test data on most Olympic athletes, cross-country skiers tend to have the highest VO2max values, followed closely by distance runners and cyclists.

While all Olympic athletes are all very physically fit, other events rely more heavily on skill including figure skating and freestyle snow boarding. For example, in figure skating completing a triple axel involves leaping into the air, spinning three and a half times, and landing backwards. On a 4 mm wide blade. On ice. Or think about the triple cork 1440, a snowboarding trick that involves flipping three times in the air while doing four 360-degree turns.

The athletes who are able to successfully complete these maneuvers have practiced for years to develop the skill and confidence needed to perform them consistently in competition. These are some of the most obvious displays of athletic skill, but all events require good technique. The development of skill in addition to fitness is the main reason why athletes specialize in one area and you don’t see people competing in both downhill skiing and speed skating, for example.

Of course, there is a psychological aspect to Olympic performances. The motivation to put in the training time alone is remarkable. Even more impressive is the ability to focus on an event despite the distractions of the crowds, media, and pressure of competition. This combination of physical and mental preparation is rare—as rare as Olympic gold medalists!

The training and preparation followed by bobsledders provides a good model for what goes into creating an Olympic athlete.

But is training alone sufficient for Olympic-level performance? Could anyone who trains enough make it to the Olympics? The answer is no, because there is another important factor in athletic performance—luck. Luck refers to genetics, which determine potential for attributes like heart size and muscle characteristics. As much as 50% of performance in some events is attributed to genetics. One sports physiologist famously answered the question, “How do I become an Olympic champion?” with “pick the right parents!”

There is more that I am missing (on purpose, because I have a word limit in my column). One additional key factor is nutrition. Despite what Subway would have you believe, Olympic athletes don’t really eat a lot of sandwiches with Fritos on them. In fact, this is a good overview of what US Olympians eat to fuel their training and competition.

Even though most of us will never become Olympic champions we can still experience many of the same benefits of training. All athletes train to develop strength, endurance, and flexibility, which is exactly what we should do, too. And those attributes will help us perform better at work (and play) and help us live a longer healthier life. It will also help us appreciate the training, dedication, and good luck that the athletes bring to the Olympic games.

Sports physiology in the Tour de France: It’s not just about doping!

My Health & Fitness column in the Aiken Standard this week is about the physiology of endurance exercise, using the Tour de France cycling race as an example. While much of the news surrounding this event has to do with the use of performance-enhancing agents, it is important to acknowledge the underlying physiology, training, and nutrition that makes it possible for athletes to perform at such a high level, with or without doping.

You learn pretty much everything there is to know about the race this year at the official Tour de France website.

The Discovery Channel made an excellent documentary about the science of cycling, featuring (pre-doping scandal) Lance Armstrong. Even though Armstrong is the focus of the show, the science applies to all elite cyclists. In fact, the show is an excellent teaching tool about the relationship between physiology, training, and equipment that is critical for performance in many sports. You can watch it on YouTube here.

Speaking of the science of Lance Armstrong… Back in 2005, Ed Coyle, Ph.D., an Exercise Physiologist at the University of Texas Austin, published a paper based on laboratory testing in the Journal of Applied Physiology about Armstrong and the physiological and biomechanical factors that may have contributed to his seven consecutive Tour de France victories.

Since Armstrong recently admitted to using a combination of performance-enhancing agents during that time, it is possible that doping and not the improved efficiency measured in the lab was responsible for his success. Coyle addressed this issue in a recent editorial in the same journal.