Olympic Nutrition and Nutrition for Us Mortals

The summer Olympics are my favorite, have you been watching? I love it because I get to live vicariously through the athletes and imagine myself running as a Team USA marathoner or as one of the tri-athletes. Ah, one can dream right? So you know when it comes to excelling at athletics 3 things must align: genetics, nutrition and training. There’s nothing you can do to change your genetics, so when it comes to making team USA it is all about training and nutrition.

Team USA has a whole crew of registered dietitians (RD) who are also certified specialist in sports dietetics (CSSD) who track the intake of and plan the meals of all of the athletes. It is based on science because there is no room for guessing when it comes to the food and hydration necessary to fuel these athletes. Even a miniscule drop in performance can be the difference between winning the gold and finishing third or fourth in an Olympic event.

Specialized Support

There is no one-size fits all approach to nutrition. Each athlete has unique needs influenced by the demands placed on their body of their respective sport. The dietitians must ensure that the athletes eat and drink the right type of fluid and fuel at the right time and in the right amount. They also assess the needs of the athletes to see if any supplements are warranted and appropriate. Supplementation is an area that is under great scrutiny especially at this level, and only supplements that are tested to be free of banned substances are used. There are very few select supplements that are supported through research and legal in the Games, two of which are creatine and caffeine in controlled amounts. There is a published list of prohibited substances that can be found on the World-Anti Doping Website http://list.wada-ama.org/prohibited-all-times/prohibited-substances/ and it includes substances such as anabolic agents, diuretics, and blood doping agents to name a few. They also break it down by sport. The IOC takes a hard stance on supplementation and doesn’t accept inadvertent doping (using a supplement that was contaminated) as an excuse. But from what I have learned from my esteemed colleagues who work with Olympic athletes, the emphasis is ALWAYS on food first and supplements second and only when necessary and where warranted. 

Hydration

Hydration is another key area for athletes. Even if an athlete is in the pool or running in cooler temps in the rain, just a mere 2% loss of body weight via sweat can mean a significant decrease in performance. At the Olympic level athletes will most likely have individualized hydration plans developed for them based on their calculated sweat rate.

Tips for Mere Mortals (myself included)

If you are outside this summer getting those workouts in despite the intense heat and humidity you will want to be certain that you following the lead of the champions and make sure you are hydrating adequately. Exercising in the heat decreases your efficiency and as you become more dehydrated you rely more heavily on your stored fuel, aka stored glycogen. This means you will tire faster due to the buildup of lactic acid (that nasty burning sensation you feel in your muscles).

If your workout is longer than 60 minutes then you will want something that includes electrolytes like a sports drink. Check the label - you want to have at least 100 mg of sodium, 30 mg of potassium, and 14 g of carbohydrate per 8 ounce serving. If you prefer electrolyte chews, they generally have more carbohydrates and less sodium but are still a good choice. Wash them down with at least 8-12 ounces of water. Electrolytes are important for fluid balance and for allowing nerve impulses to travel throughout the body. When we take a look at food sources of these minerals we find that sodium is most commonly found combined with chloride, in what we call table salt. Generally speaking, our bodies are very good at regulating our electrolyte balance. If you are not out exercising in the heat and eat a lot of processed foods then you might get too much sodium and too little potassium. But if you are out there sweating it out, then you may need a bit more salt and just about everyone could use more potassium.

The Daily Value for sodium for adults is 2400 mg, about the amount in one teaspoon of table salt. Take a look at your food labels to gauge your intake. You can also check to see if you are a heavy sweater by looking at your workout clothes for some white lines which are actually the salt from your sweat If you aren’t getting enough your body will trigger a salt craving. The Daily Value for potassium is 4000 mg and one banana has 400 mg, which means you need to be diligent about getting your fruits and vegetables every day. Good sources of potassium include fresh fruits and vegetables like spinach, kale, oranges, potatoes, tomatoes, dried beans, honeydew, bananas, and cantaloupe.

Make sure you are getting at least the minimum amount of sodium in your diet and to increase your potassium aim for at least 5-9 servings of fruits and vegetables a day and drinking plenty of water throughout the day.

Now back to the Games!

Coconut water: Is it really "natures sports drink"?

Coconut water is not something new. The liquid inside young, green coconuts has long been enjoyed in tropical countries due to its availability, cultural traditions and beliefs regarding its health benefits. But now it has gone main stream in the US and can be found in colorful juice-box style packages in a variety of flavors in most supermarkets. Sales of coconut water in the US have jumped in the last five years from near zero to $40 to $60 million dollars annually. Part of this increase can be attributed to celebrity endorsers like Madonna, Matthew McConaughy and Demi Moore who have recently invested in Vita Coco, and to the investment of Pepsi in O.N.E.. But is this drink really “nature’s sports drink” and what are the facts behind the hype? I for one am a skeptic of almost every new food or beverage that has the makings of a fad so I thought I would do some research and decide for myself.
Just the nutrition facts ma’am
Coconut water is not to be confused with coconut milk which is squeezed from the inside pulp and used as a common ingredient in many Thai recipes. Coconut water is from young green coconuts and is low in calories and a natural source of electrolytes including sodium and potassium. Eight ounces of coconut water has 46 calories, 9 grams of carbohydrates, 250 mg of sodium, 600 mg of potassium, 60 mg of magnesium, 45 mg of phosphorus, and 2 grams of protein (USDA, Nutrient Database). The electrolyte content is more than double that of traditional sports drinks with about half of the carbohydrates. So if you go buy a young, green coconut and crack it open and wash that bagel down with it after your workout then yes, it can contribute to optimal hydration and recovery. In addition to electrolytes and carbohydrates, coconut water contains other beneficial components including vitamins, minerals, antioxidants, and amino acids.
Not so fast!
There is always a rub. The commercial brands sold in the US (I looked at the nutrient data for 5 brands including Vita and Naked Juice) have a potassium content that is similar to the water fresh from the fruit however, the sodium content is much lower with an average of 35-60 mg per eight ounces. Compare this to Gatorade which contains 70 calories, 19 grams carbs, 154 mg sodium, and 42 mg potassium per serving and you will see that as a sports drink the sodium level is far too low for adequate electrolyte replacement.
Coconut Juices versus traditional sports drink
Product (per 8 ounces Calories Carbs (g) Sodium (mg) Potassium (mg)
Popular coconut waters:
Harvest Bay Original Coconut Water 47 12 25 480
Naked Juice Coconut Water 44 10 14 473
O.N.E.100% Coconut Water 44 10 44 487
Vita Coco 100% Pure Coconut Water 44 10 29 494
Traditional sports drink:
Gatorade Thirst Quencher 50 14 110 30


I also did a search for research on the use of coconut water as a fluid replacement drink for physical activity and found two studies completed recently. The first study compared rehydration after exercise with young coconut water, a carbohydrate electrolyte beverage, and plain water (Saat, et. Al, 2002). The results indicated that recovery was similar when either the coconut water or the carbohydrate beverage was ingested. However, as stated previously water straight from the nut has a higher sodium content then the commercial varieties sold in stores. The second study used a sodium enriched coconut water for testing rehydration compared to a sports drink and fresh coconut water from the nut (Ismail, et.al,2007). The results indicated that the sodium enriched coconut water was as effective as the sports drink in whole body rehydration.
Bottom line
If you are looking for a low calorie refreshing beverage with lots of potassium, then this is your drink. But in terms of recovery from exercise, I recommend sticking with traditional sports drinks. Sports drinks are specifically formulated for athletes with the amount of electrolytes and carbohydrates at the levels found through years of research to promote optimal hydration. Drinks like Gatorade contain 4-8% carbohydrate concentration (10-18 grams per 8-ounce serving), around 100 mg of sodium and 30 mg of potassium. This formula has been shown to promote fluid absorption from the intestines and encourage fluid retention in order to prevent dehydration and prolong exercise.
If you are curious go ahead and give it a try but test it during training not competition. As for this sports dietitian, I am going to wait for the results of those research studies conducted with the commercial varieties before I put it on my recommendations list.

Wow is it hot!

It sure is a hot one today in Phoenix with a high of 112! This means that you need to either get outside very early or very late to do your exercise. You also want to make sure that you are hydrating adequately.

Physiologically speaking exercising in the heat puts the most stress on your body. You are dealing with the heat gained from physical exertion as well as the hot environment. Dehydration results if you don’t take in enough fluids to keep up with your sweat losses. An average person that weighs 110 to 165 pounds can lose 2 to 4% of his body weight per hour and losses of just 2% result in decreased performance. Exercising in the heat decreases your efficiency and as you become more dehydrated you rely more heavily on stored glycogen. This means you will tire faster due to the build up of lactic acid and that is why your usual run or ride may seem so much harder this time of year.

So what do you need to do to stay hydrated? First, are you a salty sweater? I know I am! Have a look at your clothes and see if you have white stains on them after you exercise. If you do then yes you are a salty sweater. This is a good piece of information. The other thing you want to know is how much fluid you lost during your exercise. Best way to do this is to weigh yourself before and after your workout. Then for every pound lost you want to replace that with 2 cups of fluid and preferably fluid that has electrolytes.

Check the label of your sports drink. You want to have at least 100 mg of sodium, 30 mg of potassium, and 14 g of carbohydrate per 8 ounce serving. If you prefer electrolyte chews, they generally have more carbohydrates and less sodium but are still a good choice. Wash them down with at least 8-12 ounces of water. Plain water is not sufficient in the extreme heat so make sure you have a plan and hydrate early and often. More on electrolytes and the array of hydration choices out there later...