Athletes Nutrition

Presenter: Rinad Ali Course name: Clinical Nutrition

Course Code: 702

Objectives:Outline the dietary requirements of athletes

and compare to normal requirement.Outline some commonly used supplements

and the scientific basis behind it.Present an argument for or against the use

of supplements

Outline the dietary requirements of athletes and

compare to normal requirement.

Dietary requirement for normal adultsDietary requirement for athleticsEnergy Macronutrients MicronutrientsNutrition for female athletes

Dietary requirement for normal adults

Nutrient Quantity Per Day Energy 2000KcalorieProtein 50 gramsFat 70 grams Saturated Fatty Acids 24 grams Carbohydrates 310 gramsSugars 90 gramsDietary Fiber 30 grams Sodium (salt) 2.3 grams

Energy

Each athlete has unique energy requirements, which support their ability to meet total nutritional goals.

For everyday dietary planning and evaluation, energy requirements can be predicted via estimations of RMR and activity levels. Research methods such as indirect calorimetry and DLW allow energy requirements to be measured, and may be useful to confirm situations in which an athlete has a true energy balance abnormality.

Many athletes are over-focused on reducing body mass and body fat below levels that are consistent with long-term health and performance.

Restrained eating can cause significant detrimental outcomes to body function.

Leptin may be involved in modulating or mediating some of these changes.

Energy Needs Calories

Consumed CaloriesExpended

Carbohydrate

Official dietary guidelines for athletes are agreed in their recommendation of high carbohydrate.

carbohydrate intake ranges of 5 to 7 g/kg/day for general training needs and 7 to 10 g/kg/day for the increased needs of endurance athletes.

Why are Carbohydrates Important for Athletes?

Carbohydrates are one of the most important nutrients needed in an athlete’s diet.

Carbohydrates are vital to help reach peak performance during physical activity because they provide:

1. Energy 2. Muscle Gain

Muscle GainWithout an adequate amount of stored glucose in the body, other nutrients, such as fat or muscle protein, are utilized to make energy.

With the correct amount of carbohydrates available to muscles, protein can be free to do its main job of repairing and rebuilding muscle tissue, which maximizes muscle gain.

Protein

The Recommended Dietary Allowance (RDA) for protein, 0.8 g/kg of body weight per day, is designed to maintain nitrogen balance in the body for the average adult; a negative nitrogen balance indicates that muscle is being broken down and used for energy.

While maintaining nitrogen balance is critical for health, studies now suggest that the RDA may not be the amount of protein needed to promote optimal health.

To achieve that, they say, more protein is needed, and studies now suggest that athletes, active people, and older individuals require even more.

A study recently published in the Journal of Nutrition found that muscle protein synthesis was 25% higher when protein was distributed across the three meals compared to when most protein was consumed at one meal, even when total protein intake was the same.

A number of well-controlled studies are now published in which “higher” protein diets have been shown to be effective in promoting weight reduction, particularly fat loss.

Of relevance to athletes and those in clinical practice is the fact that higher protein diets have quite consistently been shown to result in greater weight loss, greater fat loss, and preservation of lean mass as compared with “lower” protein diets.

Protein-Rich Foods Beef steak (3.5 oz): 29 g Salmon (4 oz): 29 g Lentils (1 cup): 18 gGreek yogurt (5 oz): 14 gSkim milk (8 oz): 8 gTofu, firm (3.5 oz): 7 g Egg (1 large): 6 g

Protein Specific GuidelinesDevelop a meal plan that will supply adequate

calories, carbohydrate, and protein each day.Distribute the protein equally across meals.Emphasize high-quality protein.Base protein intake on weight, not on

percentage of calories.Base protein intake on the individual’s sport and

intensity level.

Fat

Adequate intake of fat is necessary for numerous metabolic activities that promote optimal health. For example, vitamins A, D, and E require fat for proper absorption. Fat intake for an athlete should range between 20-35% of total daily calories.

Current dietary guidelines recommend that 10% of fat intake should come from monounsaturated sources, 10% from polyunsaturated sources, and no more than 10% from saturated fat.

The Effect of Diet on Physical Endurance

Maximumendurance time:

57 min

167 min

114 minNormal mixed diet

Fat and protein diet

High-carbohydrate diet

MicronutrientsMicronutrients function in a variety of roles that

optimize health. They are involved in energy production, blood synthesis, maintenance of bone health, and immune function.

They also aid in the process of muscle and tissue repair during recovery from exercise or injury.

Vegetarian athletes may be at risk for low intakes of iron, calcium, vitamin D, riboflavin, zinc and vitamin B12.

Nutrition for female athletes

Inadequate nutritional intake is more common in female athletes than in their male counterparts. Proper diet is vital for active individuals to maintain adequate energy during physical activity and for postactivity recovery.

Female athletes, particularly endurance athletes, are less likely to achieve the previous carbohydrate intake guidelines. This is due to chronic or periodic restriction of total energy intake in order to achieve or maintain low levels of body fat.

Female athletes who participate in sports that encourage leanness such as gymnastics, distance running, diving, and classical ballet, have inadequate nutritional intake.[5, 6]

Koutedakis and Jamurtas found that female dancers consume less than 70% of recommended daily energy needs.[7, 8]

Female athletes are at increased risk for iron, calcium, vitamin B, and zinc deficiencies. These nutrients are vital for building bone and muscle and for energy production. Vegetarians are particularly at risk for developing deficiencies in these vitamins and minerals.[5, 9]

Some commonly used supplements & the scientific basis behind it.

References  1.Burke, L.M., Energy needs of athletes. Can J Appl Physiol, 2001. 26 Suppl: p. S202-19.2.Burke, L.M., et al., Guidelines for daily carbohydrate intake: do athletes achieve them? Sports Med, 2001. 31(4): p. 267-99.3.Phillips, S.M. and L.J. Van Loon, Dietary protein for athletes: from requirements to optimum adaptation. J Sports Sci, 2011. 29 Suppl 1: p. S29-38.4.Mamerow MM, Mettler JA, English KL, et al. Dietary protein distribution positively influences 24-h muscle protein synthesis in healthy adults. J Nutr. doi: 10.3945/jn.113.185280.5.Montero A, López-Varela S, Nova E, Marcos A. The implication of the binomial nutrition-immunity on sportswomen's health. Eur J Clin Nutr. 2002 Aug. 56 suppl 3:S38-41. [Medline]. [Full Text].6.da Costa NF, Schtscherbyna A, Soares EA, Ribeiro BG. Disordered eating among adolescent female swimmers: dietary, biochemical, and body composition factors. Nutrition. 2013 Jan. 29(1):172-7. [Medline]. 7. Koutedakis Y, Jamurtas A. The dancer as a performing athlete: physiological considerations. Sports Med. 2004. 34(10):651-61. [Medline]. 8.Doyle-Lucas AF, Davy BM. Development and evaluation of an educational intervention program for pre-professional adolescent ballet dancers: nutrition for optimal performance. J Dance Med Sci. 2011. 15(2):65-75. [Medline]. 9.Gabel KA. Special nutritional concerns for the female athlete. Curr Sports Med Rep. 2006 Jun. 5(4):187-91. [Medline].