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Endurance Athletic Nutrition

November 8, 2009 by Tim Cupery Leave a Comment

In preparation to ride the Whitney Classic with my brother-in-law, I read up a fair bit on nutrition for endurance sports.
Here’s a basic article about endurance nutrition from Hammer Nutrition, perhaps the best in the business for ultrarunning, cycling and triathlon stuff.

My executive summary of what I feel are the more important points:

1. fluid intake between 16-28 oz. per hour depending on heat and rider weight. even if you’re sweating a ton, the body can’t absorb more than 28 oz./hour.
2. the body can’t absorb as many calories per hour as it is burning, so it doesn’t help to take in lots of calories. you can only absorb 300 cal/hour and replenishment beyond that needs to be done post-exercise.
3. avoid simple sugars, complex carbs are much more effective fuel because the body is limited in how many simple carbs it can process. So Gatorade actually isn’t ideal here. (Nor is it good as a “healthy” drink for people who aren’t engaged in intense exercise, as I wrote recently.) Note that I am not critiquing Gatorade in general.
4. exercise over two hours requires protein, or muscles start to break down because the body is digesting them to get sufficient protein
5. soy (or rice) protein is better during exercise. Whey protein is quickly absorbed and better for recovery, and its use during intense exercise can result in problematic byproducts.
6. liquid fuels are preferable to solid fuels during exercise, because they are easier to digest

As applied to Graham’s and my riding the Whitney Classic: Since we weren’t riding close to aerobic threshold on the event, the liquid-fuel criteria is less important. And anyway, I see Tour de France riders taking in energy bars pretty regularly, so they can’t be that bad even for higher-intensity cycling. We did energy gels, a few bars, and Hammer Nutrition’s HEED sports drink, along with some protein supplement, and also ate some fruit at rest stops.

 

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Filed Under: Nutrition Tagged With: Carbohydrate, Fat, Gatorade, Health, Low-fat diet, Nutrition, Protein, Saturated fat, Sports drink

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Gatorade Is Not a “Health Drink”

November 3, 2009 by Tim Cupery Leave a Comment

In recent years, sports drinks have scored a major coup in terms of marketing and perception among the general public. Sports drinks like Gatorade and Powerade are designed as specialized beverages for athletes to refuel, rehydrate, and replenish electrolytes, during or directly preceding/following athletic activity.
But from a marketing angle, athletes are a small group, especially if they are only consuming the product during or directly before/after activity.
However, if average-Joe and Jane are buy sports drinks “because they’re a healthy beverage” then the market is much, much larger.

It’s not necessarily that sports drinks are marketing. Sports drinks are typically marketed by athletes, and generally marketed for athletics. Gatorade isn’t telling you that it’s healthy to drink their product while sitting on the couch watching football. (Baseball players and golfers marketing sports drinks may seem like a stretch, as they don’t sweat nearly as much as basketball and football players while in competition. But Ryan Howard and Tiger Woods work out intensively and presumably sweat a lot there.)

The typical mental process of the “health drink” consumer probably goes something like this:
– I’m thirsty and want something with flavor
– I know that soda is just empty calories
– athletes who are really healthy drink sports drinks, which help to fuel their performance
– sports drinks are healthy

Problem is, sports drinks are still mostly empty calories. Yes, they have electrolytes. But if you’re not sweating from activity, you probably don’t have need of extra electrolytes and your body will just excrete them. And aside from water (which you can get for free from the tap), the other thing that sports drinks have is simple carbohydrates – mainly sugars in the most common sports drinks. (Hammer Nutrition’s HEED contains a high ratio of complex carbs, but their only market is endurance athletics training and events.)

There is a place for simple carbs while engaged in high-intensity exercise (although the body is limited in the rate at which simple carbs can be metabolized, which is a reason for endurance athletes to go for a sports drink with more complex carbs).
But for people not sweating during training or competition, drinking simple carbs from a sports drink isn’t much different than drinking a soda, or eating candy.

The body quickly digests simple or processed carbohydrates (including simple sugars), which floods the bloodstream with sugar. If your body is not ready to use that blood sugar, it responds by upping insulin levels, which in turn causes the excess blood sugar to be stored as subcutaneous fat. And since the digestive system has made quick work of those calories, you feel hungry again quickly, and may just eat (or drink) more as a result.

“Coup” may be the wrong word, since it’s not clear that this trend was initiated as a result of marketing of sports drinks. But as businesses, they certainly don’t mind.
Of course, I shouldn’t necessarily mind either. Compared to the alternative beverages that the average American drinks, sports drinks certainly aren’t any worse than Coke or Pepsi, and on that front I shouldn’t mind seeing Powerade coming out of one of the spigots in the soft drink machine at Burger King.

But sports-drinks-as-health-drinks bothers me because it’s so inaccurate. No one is thinking that Coke is a healthy thing to drink, they just think it tastes good and refreshing. But average-Joe and Jane taking in more simple carbs through sports drinks may think they’re choosing a healthy alternative, which they aren’t.

Special cases: I recently saw a what-to-do-in-flu-season display at UNC’s campus health center, and gatorade was on one of the shelves. There may be value here, as people who are vomiting need to rehydrate, replenish electrolytes and get some easy-to-digest calories back in their system. I’ve also heard of women using sports drinks while giving birth, which is another reasonable application. However, neither people vomiting from the flu nor women in the delivery room make up a large market, in terms of volume of sales.

For more on simple carbs as a dietary problem, see our post, Eating Fat is Good For You.

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Filed Under: Nutrition Tagged With: Gatorade, Powerade, Sports drink

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General Diet and Nutrition Guidelines

October 18, 2009 by Dustin McCraw Leave a Comment

Our basic dietary philosophy can be summarized as the following rules:

  1. Eat “whole” foods as the primary source of impact. Whole grains, fresh meats, fresh fish, legumes, nuts, eggs, etc.
  2. Eat plenty of protein with every meal; it helps keep you sated, provides necessary fuel for muscle maintenance, and aid in fat loss (due to protein’s high thermic effect).
  3. Eat plenty of fat—saturated or unsaturated. Avoid processed trans fats, however.
  4. Eat sufficient amounts of fruits and vegetables; most sugar intake should be through eating fruit.
  5. Eat non-processed carbohydrates. Whole grains are beneficial, while refined carbohydrates and starches are empty calories that should be cut from the diet.
  6. Eat often. “Three square meals a day” is generally insufficient frequency; eating smaller portions more often keeps the metabolism higher and improves the body’s function both for activity and thinking.

Intro:
This list should be taken as a general guideline. It is directly relevant to 99% of us. (note: 85% of statistics are made up on the spot). There are cases where this information does not directly apply, such as to Michael Phelps (link), who has a caloric intake of 12,000 calories per day. In the case where you burn through 12,000 calories per day, different rules apply. However, the vast majority of us need a caloric intake somewhere between 2,000-4,000 calories per day. The guidelines we set forth here will help us make the best use of the calories we have available to use on a moderate to rigorous exercise routine.

Rule 1 explained:
When going grocery shopping, stick to the outside isles. There’s little need to go down the middle isles, which contain processed foods laden with simple carbohydrates, frozen processed foods, and other processed foods which have an expiration date within 1-2 years after manufacture. Foods are meant to expire, and any food which doesn’t expire probably has had many important nutrients removed during processing. Additionally, processed foods are generally more easily digestible. Easily digestible foods, such as sugar and simple carbs create an insulin spike which leads to much of the food eaten being stored as fat unless followed by intense exercise. See Rule 5.

Rule 2 explained:
Ideally, when on a decent workout schedule, you should be eating 1-2 times your weight in grams of protein each day. This amount of protein will ensure you see the maximum gains possible from your routine. If you’re not eating enough protein, your body will not be able to repair and build muscle as quickly as it would otherwise be able to do.

If you eat more protein than you need, you’re doing great (we do not recommend you eat more than 2 times your body weight in grams of protein per day, due to the excessive stress you will put on your kidneys–keep it reasonable). Protein is which isn’t used for rebuilding muscle is converted to energy at 70% efficiency, which means that you will make your body work harder to process protein into energy than any other food type. This is to your advantage when trying to burn fat, because you’re using your metabolism to give you a 30% bump in fat burning potential!

Rule 3 explained:
There is conflicting information on what types of fat are healthy and what kinds are not. It is our conclusion, from the current research, that eating natural fats is healthy, be they saturated or unsaturated. From the research, we believe that eating artificially hydrogenated fats and maintaining body fat over a certain percentage is not healthy. It is a common misconception that fat eaten in the diet is directly stored as fat on the body. However, eating fat does not mean someone will gain body fat. The body processes fat through one metabolic pathway, and it processes carbohydrates through another metabolic pathway, both of which have the potential to put fat on an individual. The only way someone can gain weight is to eat more calories during the day than they use, irrespective on whether those calories come from fat or carbohydrates.

Within the last few years, the American Heart association reversed its opinion that unsaturated fats are bad. It also appears that the recent opinion of the American Medical Association is that there is no substantial evidence that eating saturated fats is unhealthy. This is the result of a slow shift in the scientific consensus which has been occurring over the last several decades, since the initial premise that fat is unhealthy (around the 1970s).

While it is opposite the conventional wisdom, eating a healthy dose of fat in place of carbohydrates will net you several benefits. First, it takes the body longer to process fat, meaning that you stay full longer, and need less calories throughout the day. This will help you burn fat. On the topic of saturated fats, there is current research which suggests that saturated fats increase “good” fats in the bloodstream more than “bad” fats in the bloodstream giving you a net health gain. This is in addition to the vitamins and minerals, which are generally more highly concentrated in saturated fats. Additionally, fat is processed in a different pathway than carbohydrates, which means that if you eat a relatively small amount carbohydrates and a relatively high amount of fat, you will force your body to “learn” to burn fat effectively because there is no other source to pull it from. This is a great means to teach your body to burn fat efficiently for endurance training.

It is our position, however, that trans-fats should be removed from the diet. These are artificially hydrogenated fats, and are not natural. The research points to these fats being unhealthy, and as a general matter of course, most things which aren’t natural (read: manufactured) tend to be unhealthy. Stay away from these fats.

Rule 4 explained:
Fruits are an excellent source of energy. The benefits of eating fruit come from it being a natural source, a source of vitamins, an excellent source of fiber, and a source of dietary water as well. Eating natural, unprocessed foods are generally beneficial, because they take the body longer to process, and so do not generally create a large insulin spike. The fiber and water naturally contained in fruits are beneficial because they increase the volume of the food, and cause your body to expend energy preparing for digestion, but are not actually processed by your body for energy. This means you feel full, but aren’t taking in excess calories.

We do NOT recommend fruit juice. Fruit juice is, unfortunately, not natural because much of the fiber and dietary water is removed during processing. Interestingly, orange juice has the same caloric breakdown as Coke, due to its extremely high sugar content. The only benefits fruit juice has over Coke is that there is no caffeine and no syrup (processed junk) for the body to expel from the system because it can’t use it. Fruit juice does, however, have a small amount of vitamins, but we feel that there are better means of obtaining vitamins (i.e. from fats and fruits).

Vegetables are most beneficial when trying to maintain or reduce your weight. The main benefit here is that per volume, vegetables have relatively few calories and you get vitamins and minerals to boot. Point in case: if you were to eat a diet of solely vegetables, you would practically need to force-feed yourself to get the calories you need to operate throughout the day (don’t do this–you’ll miss out on the necessary protein!). In fact, some vegetables, such as celery, have a small amount of negative calories. In essence, you can eat as much celery as you want, and you’ll actually wind up burning a small amount more calories during digestion than the energy your body is able to acquire from the celery. Use this knowledge to your advantage if your trying to not go over your allotted calories for the day.

Rule 5 explained:
Simple carbohydrates and processed carbohydrates have a high glycemic index. This creates an large insulin spike which which shuttles all the energy just eaten out of the bloodstream and into the body. This is fine if you’re about to use a large amount of energy during intense exercise. However, if you’re eating processed carbohydrates in a normal setting, the body takes all the extra energy you’ve just shuttled into it and stores it as fat. To add insult to injury, when the insulin spike removes all the sugar from the bloodstream, you wind up tired and hungry much sooner than you would have without the insulin spike. So the net effect of simple carbohydrates is that is that you store more energy as fat and get hungrier quicker. Stay away from these foods!

Whole carbohydrates, while still having a higher glycemic index than fat, have a lower glycemic index than processed carbohydrates. So, if the body is given foods which have a lower glycemic index, such as whole wheat, then the food is processed over a longer period of time. This keeps your insulin levels low, keeps you full, and also allows the body to use more of your food for energy and store less as fat. Unless you’re about to expend a lot of energy, keep the simple carbohydrates to a minimum, and eat whole carbohydrates.

We prefer to get the greater portion of our diets from protein and fat for the health benefits (namely for satiation and fat burning potential), but bear in mind that your body needs some carbohydrates. The provides the power source for the muscle fibers in the body. You need enough carbohydrates to refuel your muscles after exercise, even normal everyday activity, and it’s best to obtain your carbohydrates from natural, whole, unprocessed carbohydrates.

Rule 6 explained:
Shoot for eating 4-6 smaller meals a day, as your schedule allows. The essential premise behind this rule allows us to keep a tight leash on insulin levels. By giving your body a limited amount of food at a time, multiple times a day, you can keep your insulin levels low. This limits your body’s opportunity to store that energy as fat, because it’s constantly using meals for energy for everyday activities. By keeping insulin levels low (and avoiding an insulin spike), eating small, interspersed meals will also keep you full for longer than eating the same amount of food in fewer settings. This obviously doesn’t mean eat more food. It simply means eat the same amount of food as you normally would as often as possible throughout the day.

The second reason for this, is that eating more meals increases the amount of calories you burn naturally. Every time your body prepares to digest food, it expends energy. Thus, if you eat food 6 times per day, your body will expend more energy preparing for digestion than it would have if you had eaten 3 times per day.

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Filed Under: Nutrition Tagged With: Diet, Food, Health, Michael Phelps, Nutrition, Saturated fat, Weight loss

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Eating Fat is Good For You

October 7, 2009 by jason 2 Comments

This is a post to centralize important links on dietary fat and its important role in nutrition.

Fats are Good

One of the most harmful dietary myths that has been entrenched popular thinking for many years is that dietary fat is bad. That paradigm is cracking, with much research over the last 15 years showing the fallacy of that consensus. When studies continued to fail in their attempts to produce evidence for the positive effects of a low-fat diet, saturated fat became the new culprit. As a result, most dietary advice now assumes that saturated fat is “bad fat,” while unsaturated fats are “good fats.” The problem is that saturated fats have never been shown to be detrimental in any scientific study, and the studies now being published are contradicting this theory as well.

Trans fats (which are created when vegetable oils are chemically altered to solidify them), on the other hand, should be avoided based on recent research. You’re far better off eating butter than margarine, which is loaded with trans fats. But what about butter’s high cholesterol content? As it turns out, consuming cholesterol does not appreciably increase one’s blood cholesterol; blood cholesterol is manufactured by the body, not taken in through food consumption.

Another important thing to note in the few “observational studies” typically cited to show eating animal fats (or animal products in general) to be unhealthy are usually conducted by (or sponsored by) people or groups who have an ideological commitment to vegetarianism for other reasons, giving reason to suspect the motives behind these less-than-scientific observational studies. Aside from trans fats, which fat sources should be avoided, based on the best research? Vegetable oils rich in Omega-6 fatty acids should generally be avoided; these oils include regular vegetable oil, corn oil, safflower oil, soybean oil, and cottonseed oil. Ironically, these are the oils often marketed as “healthy” alternatives.

Of course, any talk about the value of fat must be taken within the context of people’s general caloric needs. It’s easier to ingest excessive calories when eating fat, because fat packs more calories into a given volume of food (9 kcal per gram of fat, compared to 4 kcal per gram of carbohydrate or protein).

Still, studies show that it’s actually easier to ingest excessive calories when eating carbohydrates (despite their being less-calorie-dense) because of the body’s hormonal responses to each. So it’s true that excessive calories are “easier” with fat consumption, but they’re also “less likely.” It’s a dietary paradox, but one that makes sense given basic endocrinology.
Basically, this happens because simple (processed) carbs are quickly digested and absorbed into the bloodstream (especially if eaten without much protein or fat) and thus more quickly stored as fat if your body doesn’t immediately need to use that excess blood sugar. Excess blood sugar causes insulin to rise, which causes that excess blood sugar to be stored as fat. And since the digestive system has made quick work of those calories, you feel hungry again quickly, and may just eat more as a result.

Also, moderation in type of fats is still important, as the body uses different fatty acids for different nutritional tasks, and there are some fatty acids termed “essential” (EFA’s) because our body cannot produce them.

The Links:

New York Times Magazine: “What If It’s All Been a Big Fat Lie?“
This lengthy article looks at the recent work showing weight/fat gain to be closely tied to endocrine responses to sugars, etc., than fat consumption, which seems to help keep people slimmer. It also explores the origins of the “fat is bad for you” myth, tracing things back to a single poorly-constructed observational study by Ancel Keys in the 1950s. It also addresses the impact of all the low-fat diets encouraged from 80s on, suggesting that this dietary experiment may have had a large impact on current obesity problems. It’s a great primer for understanding how popular dietary ideas got so twisted for so long, with a good amount of attention paid to the politics behind the scenes.

WebMD: “The Truth About Fats“
A good look at different types of fats, summarizing much of the recent work done in the field. It still takes a bit of a conservative route with respect to saturated fat, observing that it has never been shown to be “bad” (and saying there’s no reason to avoid it) while still encouraging the reader to focus more on the fats that have been proven to have positive impacts by recent research.

Brad Pilon “Is it time to give up on Low-fat foods?“
A brief but good summary of why the low-fat diet trend was a bad idea.

Tim Ferriss: “7 Reasons to Eat More Saturated Fat“
Just what the title says: why saturated fat is healthy.

Men’s Health: “What if bad fat isn’t so bad? No one’s ever proved that saturated fat clogs arteries, causes heart disease“
This piece starts with Ancel Keys’ observational study and shows that the studies since then have contradicted his “evidence.” It also looks at the latest data on various saturated fats, showing that at worst they have a net neutral influence on blood cholesterol levels. It also explores the various political forces studies showing saturated fat to be healthy have had to deal with—scientific publication is a notoriously political process.

(New York Times) “Good News on Saturated Fat“
Gary Taubes explains the results of recent studies intending to link saturated fat to higher cholesterol and poor heart health, showing that they show no such link.

(Michael Eades) “Another China Study“
This is a very useful analysis of recent observational data from China that contradicts the famous “China Study” (a poorly-constructed observational study often cited to show that saturated fat is “bad”). The study looks at the growing obesity epidemic in China, and Eades shows that the researchers massaged the data to fit their preconceived notions, despite the data contradicting what they were trying to prove. This is a great example of how “science” is not the great objective end to all arguments but is itself controlled by politics and human subjectivity.

Studies related to dietary fat:

Dietary predictors of 5-year changes in waist circumference (J Am Diet Assoc. 2009 Aug;109(8):1356-66.)
This study by the Danish Cancer Society Institute of Cancer Epidemiology ties diets higher in saturated fat consumption (red meat consumption as well) to lower waist sizes, suggesting such a diet would lower the risk of heart disease.

Obesity, insulin resistance, and cancer prognosis: implications for practice for providing care among cancer survivors (J Am Diet Assoc. 2009 Aug;109(8):1346-53.)
This study, from the Department of Nutrition, Food Studies, and Public Health at New York University, “lays out a compelling and detailed map showing how obesity and insulin resistance interact to promote the growth of cancerous tumors. The authors argue that weight loss (if appropriate) should be a central feature of cancer prevention and treatment. Going a step further, the journal’s editors suggest that obesity (and insulin resistance) is the common culprit in all of the Dreaded Three: cancer, diabetes and heart disease” (summary taken from here). combined with the Danish study above, it seems that cancer, diabetes, and heart disease risk can all be reduced by a diet higher in saturated fats and red meat.

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Filed Under: Nutrition Tagged With: Ancel Keys, Fat, Low-fat diet, New York Times, Omega-6 fatty acid, Polyunsaturated fat, Saturated fat, Trans fat

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