As some of you know, I am running again, but sports nutrition was never my focus as a dietitian, I am trying to change that a bit, but it will probably never be the sole focus of my practice. Because of that, I am learning as I go, and will share what I learn here. I attended a session on sports nutrition during a recent dietetics conference. The woman who taught the session, Christine Bradd, MS, RD, CSCS, SCCC: http://www.rad.msu.edu/DNN/Default.aspx?tabid=588 runs the sports nutrition program for the MSU athletes.
Nutritional supplements are not encouraged; especially those which are single nutrient on the micro or macronutrient level. It is better to get the nutrition we need from foods. If someone does need to supplement food with other things, look to dry milk powder or powdered eggs added to food and drink for extra protein, Gatorade if appropriate, and Ensure, Boost or Carnation instant breakfast if extra calories are needed via liquid rather than solid form.
One thing to consider is that negative caloric/energy balance is what leads to stress fractures and the like. The body leeches nutrition. Also remember that the body needs varying types of foods for fuel, including carbohydrates, protein and fats. Too much or too little of any one will case issues. Caloric needs can be calculated simply, but if weight is changing may need adjustments as not everyone burns in the same way. For the average 19-50yr old man/woman they are as follows:
Activity level
Male Kcal/Kg/Day
Female Kcal/Kg/Day
Sedentary
25
25
Very light
31
30
Light (15grams/1000kcal. Fat should be 20-35% of an athlete’s diet, but less than 10% should be saturated fats. Protein for an athlete should be 1.2-2.0 grams/kg body weight. This number increases as activity level and caloric needs increase.
She had a very interesting slide on a marathon runner study that compared exhaustion levels/hitting the wall points with different types of dietary intakes pre run.. it said a moderate carb diet did better than a low or high carb diet. I emailed her for a reference, but am still waiting for a response.
Too few carbohydrates in the diet will lead to less glycogen storage and slower replacement of glycogen. Glycogen depletion in endurance athletes has been proven to lead to increased need for oxygen and in turn faster fatigue. It also leads to faster dehydration (1 glycogen holds 2 water molecules), and increases the breakdown of muscle tissue itself for energy. The use of skeletal muscle for energy may seem acceptable, but it decreases your training levels.
In order to build muscle mass OR lose weight (raised metabolism) it is important to eat every 3-4 hours. This is the ideal time period for nutrient absorption as well. The coaches and dietitians working at MSU have developed a power hour based on their research- having a small pre and post snack within 30-45 minutes of exercise. These snacks should ideally have protein and carbohydrates. An example if you just want a drink of something ideal would be chocolate milk. Other suggestions are apple and peanut butter, or crackers and cheese. Before exercise snacks should be 30-50 grams of carbohydrates and 10-20 grams of protein, low in fat and fiber to top off glycogen stores. After exercise should be 75 grams carbohydrate and 20 grams protein to replace the glycogen stores.
Remember hydration is very important. If you are doing less than 60 minutes of exercise in normal temps, water is plenty for hydration, more than 60 minutes, or temps over 80 degrees, a mix of water and sports drink is best. Athletes may need more fluid than they think for every pound of water weight lost during exercise you need 3 cups or 24 oz of fluid to replace it. During football practice a player may lose up to 8 pounds of fluid. The best thing is to be well hydrated before you start and stay that way. Urine color can be an indicator of dehydration- it should be lemonade colored or lighter. Apple juice color is severe dehydration starting. The body being 2% dehydrated can lead to a 25-30% depletion in performance.
Cramping can come from EITHER dehydration or glycogen depletion. Keep this in mind when deciding how to cope with it. This is the time for a sweetened sports drink as it will help with either (Gatorade for example).
Supplements:
A healthy balanced diet is best. There are supplements that can lead to inadvertent doping, or to dehydration. Creatine is one that can lead to dehydration. It is in meat products and eggs naturally. Taking too much can cause dehydration as your body uses water to process it and it attracts water when going out as waste in excess. Also some supplements can contain things that aren’t healthy. One student she saw developed a toxic level of heavy metals from using a product called muscle milk.
Protein supplements are useful in moderation if you aren’t getting enough protein in your diet, but most people who use them take too much and they crowd out the intake of carbohydrates needed to replenish glycogen in the muscles. When you consider the expense of most protein bars and supplements- think about things like canned tuna, milk, chicken breast or a scrambled egg, which are just as effective at much less cost.
Caffeine is a stimulant, and illegal in sports in quantity. It takes 1 hour to absorb. There is some proof that small amounts (1-3mg/kg) are just as effective as a larger dose in the body, and it really doesn’t do anything as far as glycogen sparing. It can moderately improve performance (still being researched) in activity that is greater than 1 hour in duration.
The big things I learned were that most stress fractures come from negative caloric balance. Athletes who suffer a lot of stress fractures often reduce them greatly by increasing caloric intake (and in turn gaining a few pounds) and maintaini
ng that intake level. Their performance often improves dramatically as well. Sleep disturbances can also be a sign of a negative caloric balance and are very negatively impacting on exercise.
Nutritional supplements are not encouraged; especially those which are single nutrient on the micro or macronutrient level. It is better to get the nutrition we need from foods. If someone does need to supplement food with other things, look to dry milk powder or powdered eggs added to food and drink for extra protein, Gatorade if appropriate, and Ensure, Boost or Carnation instant breakfast if extra calories are needed via liquid rather than solid form.
One thing to consider is that negative caloric/energy balance is what leads to stress fractures and the like. The body leeches nutrition. Also remember that the body needs varying types of foods for fuel, including carbohydrates, protein and fats. Too much or too little of any one will case issues. Caloric needs can be calculated simply, but if weight is changing may need adjustments as not everyone burns in the same way. For the average 19-50yr old man/woman they are as follows:
Activity level
Male Kcal/Kg/Day
Female Kcal/Kg/Day
Sedentary
25
25
Very light
31
30
Light (15grams/1000kcal. Fat should be 20-35% of an athlete’s diet, but less than 10% should be saturated fats. Protein for an athlete should be 1.2-2.0 grams/kg body weight. This number increases as activity level and caloric needs increase.
She had a very interesting slide on a marathon runner study that compared exhaustion levels/hitting the wall points with different types of dietary intakes pre run.. it said a moderate carb diet did better than a low or high carb diet. I emailed her for a reference, but am still waiting for a response.
Too few carbohydrates in the diet will lead to less glycogen storage and slower replacement of glycogen. Glycogen depletion in endurance athletes has been proven to lead to increased need for oxygen and in turn faster fatigue. It also leads to faster dehydration (1 glycogen holds 2 water molecules), and increases the breakdown of muscle tissue itself for energy. The use of skeletal muscle for energy may seem acceptable, but it decreases your training levels.
In order to build muscle mass OR lose weight (raised metabolism) it is important to eat every 3-4 hours. This is the ideal time period for nutrient absorption as well. The coaches and dietitians working at MSU have developed a power hour based on their research- having a small pre and post snack within 30-45 minutes of exercise. These snacks should ideally have protein and carbohydrates. An example if you just want a drink of something ideal would be chocolate milk. Other suggestions are apple and peanut butter, or crackers and cheese. Before exercise snacks should be 30-50 grams of carbohydrates and 10-20 grams of protein, low in fat and fiber to top off glycogen stores. After exercise should be 75 grams carbohydrate and 20 grams protein to replace the glycogen stores.
Remember hydration is very important. If you are doing less than 60 minutes of exercise in normal temps, water is plenty for hydration, more than 60 minutes, or temps over 80 degrees, a mix of water and sports drink is best. Athletes may need more fluid than they think for every pound of water weight lost during exercise you need 3 cups or 24 oz of fluid to replace it. During football practice a player may lose up to 8 pounds of fluid. The best thing is to be well hydrated before you start and stay that way. Urine color can be an indicator of dehydration- it should be lemonade colored or lighter. Apple juice color is severe dehydration starting. The body being 2% dehydrated can lead to a 25-30% depletion in performance.
Cramping can come from EITHER dehydration or glycogen depletion. Keep this in mind when deciding how to cope with it. This is the time for a sweetened sports drink as it will help with either (Gatorade for example).
Supplements:
A healthy balanced diet is best. There are supplements that can lead to inadvertent doping, or to dehydration. Creatine is one that can lead to dehydration. It is in meat products and eggs naturally. Taking too much can cause dehydration as your body uses water to process it and it attracts water when going out as waste in excess. Also some supplements can contain things that aren’t healthy. One student she saw developed a toxic level of heavy metals from using a product called muscle milk.
Protein supplements are useful in moderation if you aren’t getting enough protein in your diet, but most people who use them take too much and they crowd out the intake of carbohydrates needed to replenish glycogen in the muscles. When you consider the expense of most protein bars and supplements- think about things like canned tuna, milk, chicken breast or a scrambled egg, which are just as effective at much less cost.
Caffeine is a stimulant, and illegal in sports in quantity. It takes 1 hour to absorb. There is some proof that small amounts (1-3mg/kg) are just as effective as a larger dose in the body, and it really doesn’t do anything as far as glycogen sparing. It can moderately improve performance (still being researched) in activity that is greater than 1 hour in duration.
The big things I learned were that most stress fractures come from negative caloric balance. Athletes who suffer a lot of stress fractures often reduce them greatly by increasing caloric intake (and in turn gaining a few pounds) and maintaini
ng that intake level. Their performance often improves dramatically as well. Sleep disturbances can also be a sign of a negative caloric balance and are very negatively impacting on exercise.
