Aerodynamics Part 1: Air Resistance



hard ridingYou’re riding along at a speed that takes some effort. It’s difficult. What makes it hard? What do you have to overcome that is demanding all that effort to maintain your speed? You ramp it up and go faster. Now it’s even harder and it takes even more effort to maintain the faster speed. Why is it harder? What changed?

When you’re riding your bike there are four factors that resist your forward movement. One of them is gravity but gravity only comes into play when you’re going uphill. You have to provide enough power to carry the combined weight of you and your bike upwards against the earth’s gravitational field. You want to fly up the hill but the earth says not so fast.

When you’re not going uphill, gravity is not doing much of anything to hold you back but it still takes effort to move forward and the faster you go, the more effort it takes. You’re fighting against three types of resistance: drive resistance, rolling resistance, and air resistance. They all take effort to overcome but air resistance is, by far, your biggest enemy.

Drivetrain or drive resistance refers to the force you have to apply to overcome the mechanical resistance coming from the moving parts of the bike’s drivetrain. This includes factors like friction from the chain moving through the teeth on your front rings and rear sprockets and the bearings in the bottom bracket of your bike. If you’re pedaling, you’re producing drive resistance. You can reduce drive resistance by keeping your chain clean and well-oiled and by replacing the bearings in your bottom bracket when they wear out.

Another way to eliminate rolling resistance

Another way to eliminate rolling resistance

Rolling resistance refers to the force you have to apply to overcome mechanical resistance coming from the parts on the bike that are not part of the drivetrain that are moving when you’re rolling down the road. This includes things like the friction of your tires on the road and the bearings in your wheel hubs. You can reduce rolling resistance by making sure your tires are not under-inflated and replacing the bearings in your wheel hubs when they wear out.

Air resistance refers to the force you have to apply to displace the air around you as you move forward. When you move forward your body and your bike are moving into a space that was occupied by air. It would be nice if the air saw you coming and got out of your way but it doesn’t work like that. The air resists and has to be pushed out of the way. As we will see, unless you are climbing a steep hill most of the effort you are putting into pedaling your bike is being used to overcome air resistance.

watts and wind resistence_ basicThe graph on the left contains a lot of useful information about where your effort is going when you’re pedaling a bike. The graph shows how much power (measured in watts on the ordinate or y-axis) it takes to move a standard racing or road bike forward at different speeds (measured in kilometers per hour on the abscissa or x-axis). The graph assumes an average sized rider, on an average bike moving forward on a perfectly flat surface – which doesn’t describe any of us with perfect accuracy when we’re out riding our bikes. For this reason, the exact numbers shown in the graph aren’t what is important. When applied to you or me at any moment in time on a specific ride the numbers are likely to be a wee bit off. However the general relationships shown in the graph will hold for all of us all of the time.

Three of the functions on the graph show the amount of power needed to overcome rolling resistance, drive resistance (labeled Drivetrain in the graph) and air resistance (labeled Wind). The fourth function (labeled Total) shows how much power is needed to overcome all three types of resistance combined. Read the graph by taking a velocity or speed shown on the x-axis and then seeing how much power must be applied to overcome rolling, drive, air or the total resistance at that velocity by the corresponding point on the y-axis. For example, at 12 kph (kilometers per hour which is about 7.5 miles per hour or mph) drive resistance is so small it barely registers and it takes about 10 watts of power to overcome rolling resistance and another 10 watts of power to overcome air resistance.

Looking at power in terms of watts may not seem very useful if you do not have a power meter on your bike that tells you how many watts you are producing as you pedal. Another way to look at power is to think of it in terms of effort. What the graph shows as an increase in power measured in watts, can be understood as an increase in the effort it takes to ride at a faster speed. In other words, the higher the power requirement, the more effort you have to expend.

What useful information can we get from the graph?

watts and wind resistence_ function typeFirst, note that the functions for rolling, drive and air resistance all increase with velocity. The faster you go, the more effort it takes to overcome each type of resistance. This isn’t very surprising. Everybody knows it’s harder to go faster and the graph just lets us know that it’s harder for three reasons: rolling, drive and air resistance all increase with speed.

Next, consider the shape of the functions. The rolling and drive functions are linear which means they are very close to straight lines. This tells us something useful. The increase in the effort you need to expend to overcome rolling and drive resistance as you go faster remains roughly constant as your speed increases. For example, it takes the same increase in effort to overcome rolling resistance when you go from 8 to 9 mph as it does when you go from 18 to 19 mph. In other words, no matter what your current speed is, the same increase in effort will be enough to overcome the increase in rolling resistance when you go 1 mph faster.

Now take a look at the shape of the function for air resistance. It curves sharply up; it’s not a straight line. This is not good news for the cyclist. It means that equal increases in speed (for example, an increase of 1 mph) demand an ever-larger amount of effort the faster you go. For example, it takes more effort to overcome air resistance when you go from 8 to 9 mph than it does to overcome air resistance when you go from 7 to 8 mph and it takes a lot more effort to go from 18 to 19 mph than it does to go from 8 to 9 mph. In other words, overcoming air resistance gets harder and harder the faster you go. When you get to the speed where the pros ride overcoming air resistance takes enormous increases in effort to produce tiny increases in speed.

Overcoming air resistance gets harder and harder the faster you go. How quickly does the increase in effort needed to overcome air resistance ramp up?

watts and wind resistence_ key pointsLooking at the effort needed to overcome air resistance as a proportion of the total effort expended can answer this question. At approximately 12 kph (7.5 mph) overcoming air resistance is taking about half of your effort with rolling and drive resistance accounting for the other half. As you go faster, overcoming air resistance demands a larger and larger proportion of your total effort. By the time you get to 25 kph (15.5 mph) approximately 70% of the effort you are putting out is being used to overcome air resistance. When you get to 20 mph (about 32 kph) roughly 85% of your effort is devoted to overcoming air resistance. And it just gets harder after that. According to the UCI (the governing body for professional cycling) the typical average speed for a flat stage in the Tour de France is about 47 kph (29.2 mph). The power demands for overcoming air and total resistance are off the chart for our graph but from the information on the graph we can calculate that over 90% of the effort needed to maintain this speed is used to overcome air resistance.

What would riding a bike be like if you didn’t have to overcome air resistance? Reading from the graph, it takes about 100 watts of power to overcome the combination of rolling, drive and air resistance when you’re going 25 kph (15.5 mph). If you take air resistance out of the equation and imagine the linear functions for rolling and drive resistance extending beyond the 50 kph boundary on the right side of the graph and continuing to increase at roughly the same rate, that same 100 watts of power would be sufficient to move you forward (on a very rough estimate) at a speed of about 125 kph (77.7 mph).

Okay, air resistance is the problem. What’s the solution? There are many ways to reduce air resistance such as riding in a full aero position on the bike which is both difficult and uncomfortable, spending tens of thousands of dollars on a high tech aerodynamic bike and a sleek aerodynamic kit, and some simple and much less demanding riding techniques that can provide small but significant benefits. We’ll examine some of these simple techniques in Aerodynamics Part 2.

Eyeing the Line

corneringWhen you hear cyclists talking about their line they’re often talking about cornering. The line they’re talking about is the best path to ride when going through the corner at speed. While this is a good skill to practice and learn, there are many other situations where paying attention to your line is important. This is especially true for cyclists who are not experienced racers, who may not have given much thought to their line, or who may not be aware of how keeping your eye on the line can make some dangerous situations much safer.

First of all, what are we talking about when we say “eyeing the line’? Your line is simply the path you intend your bike to follow on the road ahead. Eyeing the line means keeping your eyes on this path.

Wait . . what? This is a post telling riders to look where they’re going? Duh! I know it sounds obvious but, if you’re like me, you’re going to be surprised how often you don’t really do it very well once you start paying attention to it.

If you’re eyeing your line the right way, how far ahead of your bike should you be looking? That’s going to depend on how fast you’re going. You should be eyeing your line far enough ahead that you see and have ample time to react to any obstacles that might lie in the road. Usually somewhere between 2 to 5 bike lengths ahead is about right. If you find yourself surprised by road debris that you come upon too fast or you hit potholes that you see too late to avoid, you’ve been staring at a point on the road that is too close to the front of your bike.

So far, all of this is pretty straightforward and is mostly a matter of common sense. Eyeing the line can really make a big difference, however, when you have to negotiate obstacles in your path. This is where keeping your eye on the line can make your ride much safer.

potholesRoad debris like sticks, stones, gravel, and glass and road conditions like potholes, narrow or absent shoulders, drop offs at the edge of the road, and narrow lanes between vehicles or between vehicles and the curb are all potentially dangerous obstacles on a ride. Eyeing the line is the most effective technique cyclists have for getting past these obstacles safely.

The technique is simple enough. See the problem, plan your line past the problem, and keep your eye on the line ahead as you ride past the problem.

Sounds simple but to carry it you have to overcome a natural tendency that can get you into trouble. When approaching an obstacle, people tend to either keep their eyes fixed on the obstacle or keep alternating between looking at their path and looking at the obstacle. You see a pothole and you keep looking at the pothole until you’ve gone past it successfully. You have to ride a narrow lane between vehicles or between vehicles and the curb (see the picture below), one of the vehicles is a van or truck with a rear-view mirror that’s at the same height as your head or shoulder, and you keep looking at the mirror until you get past it.

Space between carsThis is a problem because people normally move in the direction their eyes are looking. When you are on the bike, you will naturally steer in the direction you are looking. This is the reason why many riders tend to drift to the left or right when they look over their left or right shoulder to see what’s behind them.

When you’re on the bike and you approach an obstacle and keep looking at it, you have a tendency to steer your bike right at the obstacle rather than around it. If you look back and forth between your line and the obstacle, you tend to waver back and forth on your bike between riding your line and riding at the obstacle. Sometimes you steer toward the obstacle when you look at it and then overcompensate by turning too far in the opposite direction when you realize you’re heading right at the obstacle.

When any of these problems occur you may also have a tendency to slow down. Now you can find yourself in a situation where you’re veering toward the obstacle, veering away from it, your line is lost, and you’re riding so slowly it’s hard keep the bike balanced. Your bike wavers, the obstacle looms, your heart rate goes up, and you either wobble around the obstacle or have to set your foot on the ground and push past the problem. No fun.

cornerFortunately, it’s easy to solve this problem. You have a lifetime of experience moving through the world around you and this experience has made you an expert at seeing the line that will enable you to safely negotiate obstacles in your path. If you are eyeing the line at the right distance in front of your bike, you will automatically pick out a line that allows you to ride around an obstacle in your path. Trust yourself. See the line, evaluate it, trust in your ability to see a good line, and ride toward the obstacle with your eyes on the line ahead. Give a quick flick of your eyes to the obstacle as you are about to draw even with it to make sure it’s where you think it is and then snap your eyes back to your line ahead. Don’t let your eyes stray back to the obstacle for any length of time.

The first couple of times you do this you’re likely to have an overwhelming desire to look at the obstacle as you approach it in order to make sure you’re not going to hit it. However, after doing it successfully a few times you will develop trust in yourself to ride past obstacles while eyeing the line and not the obstacle. It’s fairly easy to do, it doesn’t take long to master, and it is a very useful skill to pick up. Once this approach to obstacles has become a habit, you can begin to work on the more difficult skill of looking at something without steering toward it.

Here’s another situation where the same problem occurs. Think about the difficulty new drivers have trying to keep the car moving in a smooth, straight line down the road. They tend to veer back and forth threatening to crash into whatever happens to be on either side of the road.

Eye-tracking studies with new drivers show a fairly consistent pattern. Naïve drivers tend to focus their eyes at a point on the road that is too close to the front of the car and when they notice an obstacle like a vehicle parked on the side of the road, they spend too long looking at it. The result is that they don’t see obstacles until they are close to them, they steer toward the obstacle, overcompensate when turning back toward the center of the road, see the other side of the road as a new obstacle, steer toward it, and weave back and forth down the street. The movement pattern is very similar for cyclists who are not eyeing the line.

Cell Phone BanFinally, another situation where failing to eye the line can have a large impact on cyclists. Eye tracking studies using high-fidelity driving simulators have also been done with experienced drivers talking on cell phones. In almost every case the drivers reported that their driving performance had not been negatively affected while they were talking on the phone. The eye-tracking data said otherwise. When experienced drivers talk on cell phones they revert to driving like naïve drivers. They tend to focus their eyes too close to the front of the car and tend to spend too long looking at obstacles when they see them. In other words, they stop eyeing the line properly. They also take longer to notice obstacles, are slower to react to them, and are more likely to hit them.

Be aware when you’re on the bike. If you see some clown talking on a cell phone while driving, be hyper-aware. They’re a lot less competent and a lot more dangerous than they think they are and you’re the obstacle.

Thank You and a Request

Thanks very much to all of you who bought a copy of Nutrition for Cyclists on Amazon.com. Although it doesn’t look like I’m going to start out as the Stephen King of the exercise and nutrition publishing world, the book is doing well for a writer trying out self-publishing for the first time.  I expect I owe almost all of that success to the readers of this blog because Tuned In To Cycling is the only place the book has been announced. So, thanks again to everyone who has purchased the book.  I sincerely hope you found useful information that has helped with your rides.

Now comes the request. It is very difficult for first-time authors to get noticed among the hundreds of thousands of self-published ebooks on Amazon. One of the most effective ways, maybe the most effective way, to draw readers attention to a book is a set of positive reviews.  If you’re Stephen King, the quality and number of reviews doesn’t matter very much but for an unknown author positive reviews are often the difference between success and sinking without a trace.

As I’m writing this post, Nutrition for Cyclists has only garnered one review and, unfortunately, it appears to have been written by a person who spent very little time with the book and either didn’t read or didn’t understand what they found there. A lot of work went into Nutrition for Cyclists and I’m hoping it doesn’t get lost in the clutter because of a solitary review written by a reader who missed the point.  If you bought Nutrition for Cyclists, and if you found it to be useful and valuable as a resource for making good decisions about what to eat and drink before, during and after a ride, you would be doing me a great favor if you would write a review on Amazon with some info about why you found the book to be worthwhile.  Thanks.

Nutrition for Cyclists

N4C_AmazonFirst of all, an enormous vote of appreciation and thanks to all of the readers of Tuned In To Cycling over the years who have provided helpful comments, support and motivation for me to write a book about cycling nutrition. It’s finally happened. Nutrition for Cyclists: Eating and Drinking Before, During and After the Ride is now available for purchase at Amazon.com.

The book grew out of the nutrition posts here on Tuned In To Cycling and, like those posts, combines suggestions and recommendations for what to eat and drink before, during and after a ride with information about how the body responds to endurance athletics.  To help you decide whether or not you’d like to purchase the book, I’m posting the book’s Introduction here which will give you a good idea about what’s in the book and how it relates to the posts that have appeared on Tuned In To Cycling.

If you decide to buy the book and you think it is useful for other cyclists and worth a 4 or 5 star review, I would greatly appreciate it if you would leave a review on Amazon.  Positive reviews are a huge factor in helping a self-published book find an audience among the millions of ebooks published on Amazon.

Here’s the Introduction to  Nutrition for Cyclists: Eating and Drinking Before, During and After the Ride.

Chapter 1. Introduction

Here’s a quote from former U.S. President John F. Kennedy that many cyclists know well.

Nothing compares to the simple pleasure of a bike ride.

Anyone who has spent any time on a bike knows that it’s true . . . . until it isn’t.
Here’s another saying cyclists know well.

Eat before you’re hungry, drink before you’re thirsty.

Short of a catastrophic accident, nothing can turn a pleasant, joyful or exhilarating bike ride into a nightmare faster than failing to provide your body with the nutritional support it needs to carry out the ride. Nutrition for Cyclists is designed to give riders of all experience levels useful information about meeting the nutritional demands imposed on the body by endurance athletics. Good nutrition can help you get the most out of your ride no matter what kind of ride you like to do.

Finally, one more saying that everybody knows.

Give a man a fish and you feed him for a day; teach a man to fish and you feed him for a lifetime.

Nutrition for Cyclists contains recommendations about what to eat and drink before, during and after a ride. That’s the “give-a-man-a-fish” part. However, no book can give you a recipe for what to do in every possible nutrition-related situation that might arise when you’re riding the bike. Even if a book like this were possible, would you want to memorize it so you would be prepared for anything?

Nutrition for Cyclists also contains a good deal of information about how your body works when you’re engaged in athletic activity. That’s the “teach-a-man-to-fish” part. The more you know about how your body processes food and drink, and about what can happen when there is not enough food or drink for your body to process, the better prepared you’ll be to understand what’s happening to you on the bike.

The short-term goal of Nutrition for Cyclists is to get you started with recommendations about eating and drinking before, during and after a ride. The long-term goal is to give you information about nutrition and endurance athletics so that you will be able to make informed decisions about what’s happening to you on the bike and what you can do to make it better.

The information presented in Nutrition for Cyclists is based on research findings reported in peer-reviewed journals in the fields of human physiology, and nutrition and sport science. The internet is awash with assertions, recommendations, and unsubstantiated claims about exercise nutrition. Some of this advice is supported by sound research. Much of it, including a number of widely cited and uncritically accepted ideas, is not. As will be discussed in the next chapter, focusing on information that is well supported by sound research does not mean that everything in Nutrition for Cyclists is “right” or “true”. It means that this information is the best we have given the current state of scientific research on exercise nutrition.

Nutrition for Cyclists grew out of a series of posts on Tuned In To Cycling, a blog I started in the spring of 2008. While Tuned In To Cycling has posts on many cycling-related topics, the posts on nutrition have proven to be the most popular with cyclists from all over the world. Some of the content of this book has been copied verbatim from the posts on Tuned In To Cycling, some of it is a revised or rewritten version of what’s on the blog, and some of it is new. Everything in Nutrition for Cyclists was checked against the current research literature. If a section of the book has been lifted verbatim from the blog, it means that research published between the time the original post was written and the book was published did not demand changes in the information that had appeared in the blog.

For both new readers and followers of Tuned In To Cycling Nutrition for Cyclists provides the convenience of a self-contained source for nutritional information that is organized into sections devoted to what to eat and drink before, during and after a ride. Also, publication as an ebook means Nutrition for Cyclists is conveniently available anywhere you have a Kindle or any other device with a Kindle app.

Carbohydrate Loading

This post is adapted from Nutrition for Cyclists: Eating and Drinking Before, During, and After the Ride, a forthcoming ebook which I will be publishing for Kindle on Amazon.com.

Nutrition for Cyclists: Eating and Drinking Before, During and After the Ride can now be purchased on Amazon.com.  For information about the book and how it relates to what I’ve posted to Tuned In To Cycling, please check out this post.

eating spaghettiWell-organized and popular century rides often offer an all-you-can-eat pasta dinner the night before the ride.  If you go to the dinner, you’re likely to see people putting away enormous plates of pasta and if you ask them why they’re eating so much spaghetti they’ll tell you that they’re carbo loading for the next day’s ride.  What is carbohydrate loading and is eating a lot of spaghetti the night before a big ride the right way to go about it?

The basic idea behind carbohydrate loading is that glycogen stores in the muscles and liver can be increased over the norm by following specific exercise and dietary regimens in the days before a ride.  The increased glycogen stores should then translate into a longer time before fatigue sets in due to glycogen depletion during the ride. There are three recognized carbohydrate loading methods and I will suggest an alternative approach.

The original and most severe method follows a week-long regimen. On the 7th day before the ride, you exercise to exhaustion.  This exercise bout should last a minimum of 90 minutes.  The next 3 days are a carbohydrate depletion phase during which you train lightly while keeping carbohydrate intake at only 10% of your daily caloric intake.  The final 3 days before the big ride are a carbohydrate loading phase.  You continue to train lightly while jacking carbohydrate intake up to 70% of your daily caloric intake.  It’s important not to increase your total caloric intake from the norm over the 6 days of carbohydrate depletion and loading.  During the 3 day depletion phase you replace calories normally consumed in carbohydrates with calories consumed in fats and proteins. During the 3 day loading phase your replace fats and proteins with carbohydrates.

drink-b4-thirsty-mod-4-customThink about this for a minute.  The depletion phase is an extended period of controlled hypoglycemia, essentially a 3 day bonk.  During that time you can be expected to experience all of the negative effects of bonking including weakness and lethargy, anxiety, depression, hostility, feelings of hopelessness and failure, low levels of emotional control, reduced awareness of your surroundings and confused thinking.  In addition, the immune system will be depressed and you will be more susceptible to contracting an illness that may still be present when the ride comes several days later.

A 3 day bonk is hard.  Very hard.  The second method eliminates the bonk by eliminating the depletion phase. On the 7th day before the ride you have a long exercise session but you don’t exercise to exhaustion.  For the next 6 days you engage in progressively lighter exercise sessions each day.  Some people recommend tapering the level of exercise down to a day of rest on the 6th day.  For the first half of this 6 day period you ingest carbohydrates at a normal 55% – 60% of your daily caloric intake.  For the final 3 days you ramp carbohydrate intake up to 70% of your daily caloric intake, again by replacing fats and protein with carbs.

The third method is the easiest of the three. During the week before the big ride you exercise lightly and eat normally.  On the day before the ride you do a very short, 3 minute high intensity workout.  The workout should be made up of a 2.5 minute session at 130% VO2 max which is roughly equivalent to the fastest pace you can maintain over approximately 4 minutes of all-out running or cycling.  Follow this 2.5 minute effort with a 30 second flat-out sprint.  If done properly, this 3 minute workout is going to hurt.  During the following 24 hours ingest 12 grams of carbohydrates per kilogram of lean muscle mass.  Muscle mass can vary greatly depending on age, gender and degree of muscular development.  Based on a very rough average of 35% muscle mass for men and 27% muscle mass for women the carbohydrate intake over the 24 hour period would total approximately 305 grams for a 160 lb. male and 191 grams for a 130 lb. female.

If followed correctly, all three of these methods should produce a markedly enhanced level of glycogen storage on the day of the big ride.  Neither anecdotal reports (which are basically worthless) nor research studies have reached a clear consensus on how much better or worse one method is relative to the others.  The bottom line is that all three methods are effective if followed properly.

baby spaghetti dumpNow, I’ll suggest a fourth method that is usually not discussed in the literature.  Forget about it. Don’t bother with any of this stuff.

Wait . . . what? Consider the kind of riding you do.

If your ride takes less than 90 minutes, carbohydrate loading is a non-issue because proper eating before, during and after your previous ride should have adequately prepared you for the next ride.

If your ride takes longer than 2.5 or 3 hours, you’re going to have to eat during the ride anyway because even perfectly executed carbohydrate loading isn’t going to provide you with sufficient glycogen stores to last for this length of time.  All carbohydrate loading is doing is delaying the time before you have to start eating.

Wiggins eating_croppedIf your ride takes between 1.5 and and 2, maybe 2.5 hours, carbohydrate loading might allow you to get through the ride without ingesting any carbohydrates. But why would you want to do this? If you enjoy rides that last more than 90 minutes you would be much better served by becoming proficient at eating on the bike to fully supply your nutritional needs during the ride. You get better at what you practice and if you find a way to avoid eating on the bike, you’re not going to get better at eating on the bike.

The fundamental goal of cycling nutrition is to provide full nutritional support for your ride.  A competitive race, a long organized or training ride, and a Sunday afternoon toodle around the neighborhood all make different demands on your body but whatever the ride, you will do it better and enjoy it more if you provide the nutritional support the ride needs.  The simplest and most effective way to do this is to develop the habit of ingesting small amounts of carbohydrate regularly during the ride.  The best way to develop the habit is to practice doing it.

If properly carried out, carbohydrate loading can fully support rides lasting 1.5 to 2 hours, maybe a bit more, if you don’t ingest any other carbohydrates during the ride. It’s not much use for rides lasting less than 90 minutes or more than 2, maybe 2.5 hours.  Eating properly during the ride can fully support any kind of ride you want to do. The choice is yours.

Thank You and an Update

First of all, thanks very much to all of you who are following or spending time reading Tuned In To Cycling.  I sincerely hope you are finding useful information here.

The various nutrition posts are by far the most popular posts on Tuned In To Cycling.  With that in mind, I am in the early stages of putting together a book on nutrition for endurance cyclists that will be based on and will expand upon the information that is here.  When the book is ready, I plan to publish it as an e-book through Amazon.

I am absolutely not into a “I have to get paid” model for living your life.  All of the nutrition information that is currently on Tuned In To Cycling and which will end up in the book in one form or another will stay on the blog.  New information developed for the book will eventually find its way onto the blog.  The advantage of the book should be that all of the nutrition information is gathered together in one place that can be easily accessed from any device with a Kindle reading app.  If that would be useful to you or if you would like to contribute to support my efforts to bring helpful information to you, please consider giving the book a try when it appears.

Getting the book together doesn’t mean that all writing for Tuned In To Cycling will stop.  Posts on topics that don’t go into the book will continue to appear here.

Also, an early step in publishing the book is learning about how Amazon’s self-publishing  system works.  I dug into that by publishing a guide on character creation in the recently released massively multiplayer Online game The Elder Scrolls Online.  It’s called Monkey’s Guide to Character Creation in The Elder Scrolls Online, it only costs $0.99, and if you’re interested in games like this or know someone who is, I’d be grateful if you gave it a look.

“Superstarch” and the Endurance Cyclist

cyclist with appleA comment from a reader led me to take a look at a slick website hawking a product called Generation Ucan that is marketed as delivering several “scientifically validated” benefits to people engaged in athletic activity.  From the serious beginner to the most highly-paid professional, athletes are notorious for their susceptibility to being taken in by products that claim to improve performance.  The Generation Ucan website has several of the characteristics that are often associated with nutrition scams that make fabulous claims while trying to sell untested or poorly tested junk to gullible people so I decided to take a closer look.

What is it?

waxy-maize-starch_2 (2)Generation Ucan is hydrothermally modified waxy maize starch.  The starch is processed under conditions of higher than normal moisture (hydro) and heat (thermal) which changes the chemical properties of the starch molecules.   One effect of this treatment that is of interest to endurance athletes is that the carbohydrates in hydrothermally modified starch have a low glycemic index.  Generation Ucan calls HMS “superstarch” which is such an obvious and ridiculous marketing ploy that I’ll avoid it.  What they’re selling is hydrothermally modified starch or HMS.

sciencequizlogoThe Generation Ucan website is filled with phrases like “lab tested”, “scientifically proven”, “our science”, and “proof/validation”.  First of all, reputable research scientists virtually never talk about “proof” like this.  We talk about the extent to which the experimental evidence supports or fails to support the conclusion.  The marketing-hype alarm goes off big-time when “science” and “proof” occur together in product marketing.

What scientific evidence does Generation Ucan actually provide?

The website has links to a couple of white papers that talk about research that supports their claims for their HMS.  White papers are documents produced by a company with the aim of selling a product.  Generation Ucan’s white papers reference “internal studies” as evidence that HMS is wonderful.  As evidence to support their claims about HMS, these internal studies are worthless.  Not enough information is given to determine whether the research was carried out rigorously and properly.  The internal studies may provide good evidence or they may not.  There’s no way to know one way or the other.  However, if the science was good, you would expect it would have been published in a top-rated peer-reviewed journal.  There is no indication on the website that these internal studies were submitted to a reputable journal or survived a rigorous peer-review process.  Basically, the white papers contain a lot of unsubstantiated claims tricked up to look like science.

The Generation Ucan website also provides a prominent link to an article in Men’s Health Magazine that promotes the product.  Men’s Health Magazine?  Lol, really?

Buried in the science section of the website they have a link to downloads.  Follow that link and what you mainly find are sales kits.  Sales kits in the scientific evidence section?  There are seven of these sales kits.  There are also two links to their own white papers, and one link to an article in the journal Nutrition about HMS.  Nutrition is a peer-reviewed journal and this article is the only reliable scientific evidence that I found on the Generation Ucan website.

cyclist in labThe article in Nutrition is the real deal although it should be noted that Generation Ucan funded the research project that is reported in the article.  What does it report?  Nine male cyclists engaged in a 150 minute cycling session at 70% VO2(max) – that’s fairly intense – followed by a 100% VO2 (max) time-trial to exhaustion.  Before the exercise session and immediately afterwards the cyclists were given either HMS or maltodextrin.  Maltodextrin is a sweetener often used in candy, soda and many other products.  HMS and maltodextrin are both sources of carbohydrates.

Note that they didn’t call their HMS “superstarch” when they submitted the research for peer review.   If they had, they would have been laughed out of the room.

Ucan insulin dataThe study found that the HMS group had a lower initial insulin spike than the maltodextrin group.  They also found that the HMS group showed a higher level of fat breakdown during the recovery period.  There were no reliable performance differences between the HMS and maltodextrin groups during either the 150 minute exercise period or the time-trial to exhaustion that followed.  There was also no reliable difference between the two groups in the level of fat breakdown during exercise.

The authors of the article note that the increase in fat breakdown during the recovery period after exercise was probably due to the HMS that was given after the exercise period.  Their research doesn’t test this hypothesis but it is plausible given what is known about the effects of HMS and the relationship between insulin and fat burning.   Insulin is prominently involved in the regulation of fat oxidation.  Lower levels of insulin correspond to higher rates of fat burning and vice versa. The study in Nutrition provides good evidence that HMS reduces insulin and reduced insulin typically produces higher levels of fat oxidation.

Keep in mind that this study in Nutrition is the only reliable scientific evidence that is given on a website that heavily stresses the scientific basis for their claims about how wonderful their product is for athletes.  While this isn’t much, it’s more than you often get on websites that sell wonder foods for sports nutrition.  There is some real science here.  The study provided good evidence that HMS reduces insulin levels.  This information could be of interest to people who are looking to lose weight because reduced insulin levels correspond to higher levels of fat burning after exercise.  It’s worth repeating that the study showed no differences in performance between those who exercised after ingesting HMS and those who ingested maltodextrin.

What claims does Generation Ucan make about their product based on this scientific evidence?

snake-oil-salesman-bigThey claim that their HMS produces “optimized performance”, “sustained energy”, “enhanced fat burn”, “speedier recovery” and “no gastric distress”.  The claim about enhanced fat burn is supported by the evidence in the Nutrition article.  The scientific evidence they reference on the website has nothing at all to do with sustained energy, speedier recovery or levels of gastric distress.  As far as “lab tested” or “scientifically proven” these claims are completely unsupported by the scientific evidence the Generation Ucan people provide.  They give you no good reason to believe HMS provides any of these benefits.

The claim about optimized performance is outrageous.  I expect many people looking at the Generation Ucan website uncritically will understand this as meaning that performance is better if you use their HMS than if you use other carb sources during exercise.  The article in Nutrition that is offered as the only reliable scientific evidence given on the website flatly contradicts this interpretation.   There was no difference in performance (or fat burning during exercise) between the HMS group and the maltodextrin group in the study.

lawyerI have no doubt that company lawyers can parse the “optimized performance” statement to mean that Generation Ucan’s HMS produces optimized performance in the sense that it matches the “optimal” performance levels expected after ingesting carbs from candy, soda or energy drinks.  When you have to rely on lawyers to weasel out of charges of false advertising, there’s clearly something wrong.  Anyone with a lick of common sense can see that, at best, the “optimized performance” claim is highly misleading.  At worst, it is pure bullshit designed to sucker you into buying their product.

What’s the take-home message about Generation Ucan’s HMS?  The product is likely to lower insulin levels.  This can be useful to people who want to burn fat.  If this is one of your goals, taking Generation Ucan’s HMS immediately after exercise may be useful.  If you are diabetic, don’t go near this product without consulting your doctor.  As far as supporting performance during exercise, their HMS is unlikely to be any better, or any worse, than many other sources of carbohydrates you can eat or drink on the bike.

What’s the take home message about the Generation Ucan company based on how they present themselves on their website?  Either the people who are trying to convince you to buy their HMS have the scientific training to tell the difference between good science and junk science or they don’t.  If they do, then the science heavy promotion on the Generation Ucan website is purposefully designed to mislead you into buying their product based on unsubstantiated claims that they figure you are either too ignorant or too stupid to recognize for what they are.  If they don’t, what are they doing marketing their product with a website that goes heavy on the science?  In either case, why should you believe anything they have to say?