August 13 – Sports Nutrition Series: Eating for Endurance Athletes

Why are we talking about sports nutrition? Well, the Summer 2012 Olympics in London just finished yesterday, and many have likely been inspired to get into tip top shape!

Sports nutrition is definitely a complex topic -will just cover eating for just endurance athletes this week (and eating for strength athletes will be discussed next week).

What type of diet should an endurance athlete be following?

According to RD411 (a reputable nutrition web resource), the main goal is to keep up your body’s source of fuel through what you eat before, during, and after exercise.

Carbohydrate:

Carbohydrate intake is crucial all the time! Before, during and after long exercise bouts in order to load up, preserve and replace glycogen, carbs are needed in your diet. Foods high in carbohydrate should provide the majority – 55 to 60% – of total calories, or 6 to 10 grams of carbohydrate per kilogram of body weight. To little carbohydrate intake, and a phenomenom called “hitting the wall” may occur. This is when your muscle glycogen stores are depleted, and usually occurs after 32km (of a marathon, for example).

Emphasize complex carbohydrates. These are whole grains, breads, cereals, beans, pasta, potatoes and other starchy vegetables. *Note* to retain a diet high in fibre, keep the peels on vegetables, and choose grain products with 5g of fibre or more per serving!

Simple sugars – fruits, juices, sugar, syrups, and honey – provide “quick energy.” Many are too concentrated to be consumed during exercise -but are a good way to begin replacing glycogen stores immediately after exercise.

Protein:

Protein is needed to:

  • repair exercise-induced muscle damage
  • provide a small amount of energy during exercise (with adequate carbohydrate intake)
  •  support gains in lean tissue mass (not as common for endurance athletes)

Endurance athletes should eat 12-15% of total calories from protein, or about 1.2 to 1.5 grams of protein per kilogram of body weight. More protein than this amount has not been scientifically proven to make significant improvements in endurance athletic performances! T

Interestingly, the typical diets of most athletes provide more than enough protein to cover the increased amounts that they may need, however it is important to spread your protein intake out over many small meals during the day. Good protein sources include lean meats, poultry and fish; nonfat or low fat dairy products; eggs, grain/legume/dairy combinations.

Fat:

Provides:

  • energy
  • essential elements of cell membranes
  • fat-soluble nutrients such as vitamins A, D and E

Athletes should consume 20-30% of total calories as fat… too high or too low can have negative effects on blood lipid profiles (high LDL cholesterol levels, or “bad” cholesterol, for example).

So what should your hydration plan look like?

During exercise, water is all you need for events lasting less than 1 hour, but beverages containing carbohydrate and sodium are recommended during exercise lasting longer than 1 hour. This is where sports drinks can play a role many of which contain 7% carbohydrate – the optimal concentration!

Here are some great hydration guidelines from RD411:

2 hours before event 2 cups cold fluid
15 minutes before event 2 cups cold fluid
During event, every 15-20 minutes 4-6 oz. cold fluid (1/2-3/4 cup)
After event 2 cups fluid for every pound lost

Take home message for eating for endurance athletes:

Combine whole grains, protein-rich foods and vegetables and/or fruit at each meal and snack to help prevent large fluctuations in blood glucose, control appetite and eat a balanced diet including enough fluid to stay hydrated and energized! Also, don’t try anything new on race days, and keep pre-race meals and snacks low in fat and not overly high in fibre in order to prevent any potential stomach upset!

Until next time! Click here to listen to the podcast!

 

Image source: chumpysclipart.com

July 30: World AIDS Week

This week was World Aids week, so we talked about the difference between HIV and AIDS, how it effects your immune system, and how one would alter their diet and food handling under these circumstances.

  • HIV = Human Immunodeficiency Virus
  • AIDS = Acquired Immunodeficiency Syndrome

About 70 000 Canadians are currently HIV +. HIV is the virus that causes AIDS. A person can get AIDS after a prolonged period of being infected by HIV and if they do not care for that illness properly. Most common ways of being infected include:

  • Blood transfusion (sharing needles, medical blood transfusion, tattooing etc.)
  • Sexual intercourse
  • Open wounds
  • Born to a HIV + mother

HIV depresses the immune system by hijacking the hosts DNA and it replicates itself, which eventually breaks down the hosts immune (CD4-T cells). A person can live for a long time without feeling any symptoms. However, people are more vulnerable to opportunistic infections. AIDS is the result of uncontrolled symptoms resulting from HIV.

Food and Nutrition: Weight loss is a major issue, so it is recommended 20-30% of an energy (calorie) increase is necessary, mostly from carbs. Some micronutrients may be necessary.

Safe food handling is essential. Avoid raw meat sources such as runny eggs, deli meats, ceviche and carpaccio for example. Some molded cheeses should also be avoided. Because the immune system is depressed overall, all foodsafe principles apply, such as keeping cold foods cold and hot foods hot and avoiding cross contamination.

The good news is, there have been many medical advances and research related to HIV/AIDS and it is becoming more manageable to live with.

Resources:

www.aidsvancouver.org

HIV Helpline: 604.696.4666

HealthLink BC: 811

To listen to the full clip, please click here.

July 23: Alcoholic Beverages and Your Health

This segment covered the serving sizes, effect on your body, and benefits and drawbacks of alcohol.

Standard guidelines for consumption has been developed for Canadians to avoid binge drinking:

  • 1-2 a day for women
  • 2-3 a day for men

Standard Serving sizes:

  • 12 oz. is for coolers and beer and is 5% alcohol
  • 4 or 5 oz. is for wines and is 12% (although there are some at 7%)
  • 1.5 oz. is for hard liquor (rum, gin, whiskey) and is 40%

More alcohol is absorbed in your small intestine than in the stomach. It can take about 20 minutes for the alcohol to hit your bloodstream. Having a meal can help reduce the rate at which the alcohol is released in your blood and it is recommended to eat while you drink.

Alcohol is a high energy drink; it is metabolized at 7 kcal/g, which is considered ’empty calories’. Here is a comparison:

  • Fat = 9 kcal/g
  • Alcohol = 7 kcal/g
  • Protein & Carbs = 4 kcal/g

Wine can be beneficial to health, particularly heart disease risk if consumed in moderation. Above one or 2 drinks per day, reduces the protective affect and is not then recommended for health.

The key is to enjoy in moderation throughout the week and avoid binge drinking. Additionally, watch out for those extra calories consumed with mix and snacking!

To listen to the full clip, please click here.