FIS Medical Committee Educational Series
Dr. Bob Morrell
Member of the FIS Medical Committee
Fit to Ski - Nutritional Concerns
Carl Petersen B.P.E., B.Sc.(PT)MCPA & Patricia Chuey MSc., RDN & Dr. Bob Morrell (FIS Medical Committee)
Skiing and physical training can be both an aerobic and an anaerobic activity, and the fuel sources for both need to be adequately replaced. During gate training, skiers are required to go hard for bouts of 10-120 seconds. Depending on the drills, training sessions may last from 1-2 hours and be repeated twice a day. Training camps require similar demands and may last from 3 days to 2-3 weeks.
The primary energy source for muscle and nerve cells while doing this type of anaerobic (fast, less than 2 minutes) work is glycogen. Glycogen comes from eating simple and complex carbohydrates (CHO), i.e. fruits, vegetables, grains, pasta, bread, and cereals. Simple and complex CHOs are classified by the number of sugar units present in their chemical structure. The five most common simple sugars are glucose, fructose, maltose, lactose, and sucrose. The four most common sources of complex CHOs are rice, wheat, corn, and potatoes.
Carbohydrate foods are given a "speed rating" (glycaemic index) of fast, moderate, or slow, depending on how quickly they affect blood sugar levels. Listed below are the "speed ratings" of a variety of foods, particularly simple and complex CHO sources. These are all compared to a glucose drink, which is set as a standard of 100%. Foods rated from 70-100 or more are considered "fast", from 50-69 are "moderate," and below 50 are "slow". Glucose, maltose, and foods derived from corn and potatoes give faster blood sugar responses than porridge, for example, as shown in the chart below.
How Foods Affect Performance
An awareness of the glycaemic index of carbohydrate (CHO) foods is important for athletes. The type of CHO eaten prior to or during exercise is of significance to athletes involved in snowsports, since eating fast CHOs as part of the pre-activity meal may cause a large shift in the blood sugar, which in turn can have a negative effect on skill development or performance, due to fatigue and inability to concentrate. Fast CHOs can go as far as doubling the resting blood sugar level within one hour of eating. This response triggers a compensation reaction, resulting in a drop in blood sugar to below the resting level within 1-3 hours after eating. This "rebound" effect can often occur just as play is starting or in the middle of a match.
|FAST (speed rating)|
|maltose||glucose**||carrots||Cornflakes||bread (whole meal)|
|parsnips||potatoes (inst)||white bread|
|Puffed Wheat||white rice|
MODERATE-SLOW (speed rating)
|brown rice||spaghetti (white)||spaghetti (whole meal)||butterbeans||kidney beans||soya beans|
|shredded wheat||All Bran||porridge oats||blackeye peas||lentils||peanuts|
|Ryvita||sweet potatoes||sponge cake||chick peas||fructose||bananas|
|raisins||sucrose||tinned beans||ice cream|
|Mars bar||sweet corn||skim milk|
Symptoms of rebound
Controlling the Blood Glucose Response
Unfortunately, situations occur in which slow CHO sources are not available or are not prepared in a suitable form. In this case, the effect of the fast CHOs can be reduced by eating raw, lightly cooked or unprocessed forms. For instance, a raw apple will have less risk than would applesauce. All fast CHOs should be taken with fiber-rich foods which assist in slowing the blood glucose response.
Essentially, the key for skiers is to choose meals and snacks as outlined below.
Obviously, these symptoms are not conducive to skill development or performance. In the light of this information, it makes sense to recommend a pre-competition meal of slow CHOs, such as fresh fruits, vegetables, grains, cereals, breads, pasta, and beans, together with lean protein.
Replacing Glycogen Stores
Since glycogen stores take 24-48 hours to replenish, they must be replaced daily, using slow and moderate CHOs. To aid in glycogen storage, water should be consumed along with this CHO. It takes 3 grams of water to store 1 gram of glycogen.
It is best to replenish CHOs within 20-40 minutes following exercise, this way it takes only 12-16 hours to reload your muscles.
However, at this time there may be very little appetite or opportunity. Using a liquid CHO allows for glycogen replacement and also promotes hydration. Using a CHO supplement mixed with water or skim milk immediately following strenuous activity will help replenish glycogen stores. This is particularly important in order to help prevent fatigue when traveling a long distance, and training and racing day after day especially at high altitude.
ABC's of Ski Nutrition
A proper diet and nutritional knowledge are essential elements of training that should not be ignored until the night prior to a competition. There are a few simple steps one can take to maximise nutritional preparation for ski training and competition. The following ABC's of meal planning have been adapted from guidelines specified by Sport Scientist Dr. Istvan Balyi.
Step A: Advance Planning
Planning for a balanced diet should be an ongoing and daily part of training. This way a routine is established which can be followed prior to heavy training sessions or competitions. All meals should include a good mix of protein and carbohydrates.
Roughly 1/3 of each meal plate should contain protein and the remaining 2/3 or more should be carbohydrate.
Protein helps to build muscle tissues and cells that may be damaged with exercise. Carbohydrates ensure adequate energy stores in the muscle tissue. Choose lean protein foods wherever possible and drink plenty of water. (Carrying a water bottle and using it will assist in this matter.)
In addition to ensuring the body stays hydrated, water helps to modify the appetite and may help the body metabolize stored fat. To ensure adequate hydration, it is also vital to avoid alcohol within 6 hours of strength or anaerobic training. Alcohol may cause hormonal changes that can inhibit the adaptive process, resulting in a loss of the effects of the training session. If you do use alcohol, be sure to drink twice the amount of water to promote hydration. If you crave the taste of alcohol, try de-alcoholised beer or wine. Ideally, stick to caffeine-free beverages, such as fruit juices or herbal teas.
A further advanced planning suggestion is to eat in the early evening and avoid overeating because it puts stress on the digestive system and may not allow for adequate relaxation and sleep.
MEAL A SUGGESTION (Pre-Race Dinner):
Step B: Breakfast before Activity
MEAL B SUGGESTION (Breakfast):
Step C: Competition Food
Eat light, and ensure low fat carbohydrate choices from the slow-moderate groups. Avoid overeating. Drink water more frequently and in small quantities. Try to eat this meal 2-3 hours before your competition.
MEAL C SUGGESTION:
Step D: Replenishing Carbohydrates
Be sure to plan for post-competition or training replenishment of carbohydrates and fluid. This helps prepare the body for the next day's activities. Obviously, if training and racing day after day, you will need to maintain your consistent balanced diet.
MEAL D SUGGESTION:
Post Exercise Carbohydrate Supplement
(Approximately 50-70 grams CHO)
Fit to Ski -Nutritional Tips
Top 10 Recovery Foods for Athletes
With Dallas Parsons, RD/Sport Dietitian
|Food||Serving Size||Calories (kcal)||Carb (g)||Protein (g)||Fat (g)|
|1. 1% chocolate milk||2 cups||320||54||16||6|
|2. Low fat (1% M.F.) fruit yogurt||175g||150||26||6||2|
|3. Peanut butter & honey sandwich||1||430||73||13||14|
|4. Cinnamon raisin bagel||1 small (71g)||200||39||7||1.7|
|5. Sports Drinks (read label)
(carbohydrates & electrolytes)
|6. High Carbohydrate Energy Bars(read label)||1||varies||varies||varies||varies|
|7. Dried fruit bars (read label)||1||varies||varies||varies||varies|
|8. Bananas||1 large (118g)||109||28||1.2||0.6|
|9. Low fat granola cereal (Go Lean)||¾ cup (40g)||120||28||8||1|
|10. Meal replacement drink||1 can (227ml)||240||41||10||4|
Sport Nutrition Supplements
In the competitive spirit of sport, it is inevitable that supplementation is often part of an athlete’s training diet. Sport nutrition products can be used for convenience, to provide the body with fuel before, during and after training, but for the most part, nutrition should come from whole grains, fruits, vegetables, lean protein and low fat dairy. Under the existing regulatory environment, there is no way to accurately identify all of the constituents of every ingredient found in supplement preparations. Consequently there is no way to guarantee the safety and purity of these products. Talk to your sport dietitian before using nutritional supplements.
|Sports bars||Before, during and after training||Should have carb to protein ratio of 4:1 and < 3g fat/100 cal|
|Protein bars||After training or as snack||Provide between 12-35g protein/bar; common protein. sources are whey and soy|
|Sports drinks||Before, during and after training||Should have 4-8% carbohydrate solution and include sodium; may also have calcium and magnesium|
|Energy gels or fruit chews||Before, during and after training||Supply quick energy; electrolyte content varies|
|Protein powders||After training or part of a meal or snack, for weight gain, or travel||Check whether also supplies carbs; may be artificially sweetened|
|Meal replacement drinks||Before or after training||Quickly digested & provide fluids, good for a “nervous” stomach before competition|
|Vitamins and minerals||Daily||Individual requirements should be assessed by a dietician or physician|
Tips for Nutrition When Traveling
Finding proper nutrition on the road can be difficult. Regardless of whether you are training or competing you need to consume high carbohydrate, low fat food to optimize performance. A little thought and planning will help ensure you get good nutrition away from home.
Adapted from the SNAC Card "Checklist for the Traveling Athlete & Coach", produced by the Sport Nutrition Advisory Committee of the Sport Medicine and Science Council of Canada.
Sample High Carbohydrate Low Fat Snacks (no refrigeration necessary)
Two months before heading off for training take a detailed look at your diet. Does it provide the vitamins, minerals, proteins, fat and carbohydrates that your body needs to perform? Follow Canada's Food Guide to Healthy Eating or the USDA's food pyramid by consuming a variety of foods each day. It's also recommended that you should talk to a dietitian.
Canada Food Guide - www.hc-sc.gc.ca/fn-an/food-guide-aliment/index_e.html
USDA – Food Pyramid www.mypyramid.gov
contact e-mail Bob Morrell: firstname.lastname@example.org