Wednesday, August 12, 2009

It'll make you weep

No we are not talking about onions. It is the "advice" that is being given to my community. I assume, as I have never met one, that dietitians are wonderful caring people who got involved in diet because the care for people, just like doctors and nurses. Unfortunately the get taught that the RDI for vitamins is all that people need, and that the food tables are correct. This results in a major focus being energy intake (fat/carbo's) instead of maximizing "minor" nutrients like vitamins.

Thus some very unusual recommendations occur. Sport Waikato has a project called Team Energize. They have tips that are put into our school newsletter. Yesterday's newsletter had "Sports Nutrition Tip #10" and it stated
"After your game try to eat something straight away to help your body star its recovery.

Try a ripe banana, jam sandwich with white bread, small can of creamed rice, crumpets of fruit smoothies And remember to drink lots of water to replace what you lost."
I find it abhorrent that these people are recommending a jam sandwich with white bread! Don't think you could get any more unhealthy than this. Same as a can of creamed rice or crumpet. They are suggesting these things as they are high in carbohydrates and you use up carbohydrates in exercise, so on the face of it these recomendations seem logical. However they are not.

To make matters worse most of the suggestions are all high glycemic foods. That is foods that should not be eaten by diabetics because they cause blood sugar spikes. In non diabetics these foods cause blood sugar spikes just they don't kill you like a blood sugar spikes can do to a diabetic. No wonder our nation is crippled with an obesity and diabetic epidemic.

Let us become more rational and look at some facts.
  1. Firstly you don't need to eat to replace energy loss during exercise. You body uses the glucose (technically it is glucose 6-phosphate but let not split hairs) to drive your cell. Once all the glucose is used up additional glucose is supplied by the liver. This is because the liver stores glucose ready to distribute under exercise. This storage in the liver is called glycogen. Also once the oxygen in used up the cell instead of producing carbon dioxide as waste produces lactic acid. Post exercise the glycogen is rebuilt in the liver. It is either rebuilt from the lactic acid, or from changing fat into carbohydrates to be stored as glycogen. Fat is a very efficient storage of energy. It only takes the energy in 1 gram of fat to power the body to run 100km. Most people have a fat gram or two that could be consumed by the body without any problems. Thus you do not need to eat post exercise.
  2. I would suggest the need to eat after exercise is because we don't eat before hand. We get the stitch if we exercise on a full stomach. Thus when we finish our exercise our stomach is empty so we are hungry. When it comes to kids they are aways hungry !
  3. What your body needs post exercise is nutrients. To make energy you have to use B vitamins. Just like anything you use enough times, B vitamins wear out. Therefore post exercise you should replenish these vitamins. (You can use this trick in endurace events. I always take lots of B's when tramping it enables me to go further and faster than I normally would)
  4. Antioxidants. During exercise you body uses antioxidants to protect the body from the negative side effects of exercise. The higher oxygen use results in high oxidation, high oxidation means more rapid use of antioxidants
  5. Therefore the best thing to eat after exercise are high nutrient foods. For example a green vegetable juice (high in B's) mixed with high antioxidant foods eg berries, really fresh fruit (what ever is in season). These foods have plenty of carbohydrates that would help rebuild glycogen, and high in nutrients.
  6. Lastly if you are having fruits and vegetables these are mostly made up of water, so water intake does not need to be as high post exercise.

No comments:

Post a Comment