Nutrition and Health

Archive for May, 2010

Pre-competition guidelines

To begin exercise in a well hydrated condition with high carbohydrate (CHO) stores.

•  Aim to eat approximately 200-300g of CHO 2 hours prior to competition. If  you find that too early to eat prior to a morning event or training session you could try using a liquid meal replacement like Sustagen, or a smoothie and/or a sports drink to ensure you are getting enough CHOs.

•  This pre-competition meal should be:

1.  Low in fat.

2.  made up of low-medium GI foods, e.g. wholemeal toast, Special K, muesli bars, yoghurt, bananas.

3.  low in fibre, therefore avoid apples, kiwifruit, wholegrain breads etc as they’ll make you want to go to the loo.

•  Drink fluid (water or electrolyte drink) with the meal, at least 300-600ml, then 150-300ml every 15-20 minutes up until approximately 45minutes to an hour before the event.  Again, this will depend on how your bladder can handle fluid!

During Competition guidelines

Priorities: Fluid, sodium and CHO replacement.

•  It is important that you continually consume fluid as much as is practical and comfortable in an attempt to match sweat losses. Aim to consume 500-1000ml of fluid per hour. If you feel thirsty you are already dehydrated so don’t rely on your thirst to remind you to drink.

•  A sport’s drink containing CHO & sodium can be a good way of ensuring sodium and CHO levels are maintained in a long training session (2hours +). Adding CHO to a sport’s drink also promotes water absorption in the small intestine, providing the concentration is not too high.

•  During training camps or tournaments aim to consume 30-60g of High GI CHO foods per hour. Examples of high GI foods are gummy lollies (jet planes, wine gums, snakes), ripe bananas, low fibre muesli bars, vanilla/super wine  biscuits etc.  Apples, oranges, fruit juices etc are not good foods to consume as their CHO content is made up mainly of sucrose (fruit sugar), which takes considerably longer to empty from your stomach.

Assure that astronaut diets are adequate in all nutrients for the duration of each mission .

Maintaining the potency of essential nutrients in foods flown on spacecraft is critical for crew health and safety.  By definition, humans are not able to synthesize essential nutrients in the body and thus depend 100% on an adequate supply in the diet.  It is well documented, on Earth, that food processing and long-term storage can diminish, and in some cases obliterate, nutrient efficacy.  It is unknown what the effects are of current processing techniques used by NASA (thermostabilization, dehydration, and irradiation).  The goal of our Team is to document nutrient potency of space foods as eaten in space, so that we can be assured that when astronaut diets are designed to deliver  appropriate nutrients the nutrients are actually in the foods.

Develop an understanding of nutrient requirements in space that is sufficient to appropriately design diets to meet those nutrient requirements. Nutrient requirements in space are not the same as those on Earth.  Without knowledge of the differences in requirements in space vs. on Earth, it is impossible to design diets that meet nutritional needs for astronauts.  Data pertaining to nutrient requirements in space are extremely limited.  Despite this, several  deficiencies/insufficiencies are consistently reported.  These deficiencies include inadequate energy intake, depressed vitamin D, K and folate status, and diminished antioxidant capacity.