Introduction to Sports Nutrition
Original Editor - User Name
Top Contributors - Wanda van Niekerk, Jess Bell and Lucinda hampton
Basics of Nutrition[edit | edit source]
Macronutrients[edit | edit source]
Macronutrients provide calories or energy to the body.[1] Their function is to promote:
- cellular growth
- metabolism
- maintenance of normal bodily functions
Macronutrients are necessary in large amounts to provide a full and proper effect. The three types of macronutrients are[1]:
- carbohydrates
- proteins
- fats
Carbohydrates | Proteins | Fats |
---|---|---|
|
Micronutrients[edit | edit source]
Micronutrients are essential, but we need these in smaller amounts.[12] Micronutrients are necessary for cell growth and function. The human body can not produce micronutrients so it must be consumed.[12]
Vitamins | Minerals and their function |
---|---|
Water[edit | edit source]
- Water is best for hydration, but any calorie-free, non-caffeinated, non-alcoholic fluid can work
- Caffeine and alcohol function as diuretics[14]
Food Groups[edit | edit source]
Fruits | Vegetables | Protein | Grains/starch | Dairy | Fats |
---|---|---|---|---|---|
|
|
|
|
|
|
MyPlate provides good examples of healthy eating. Read more here.
Sports Nutrition[edit | edit source]
Energy Balance and Exercise[edit | edit source]
All info from: Chapter 5: Energy Requirements and Measurement of Energy Expenditure
- Energy balance is important for athletes wanting to change their body mass and/or body composition in order to improve performance or make a specified weight category for their sport.
- Insufficient energy consumption in relation to expended energy will result in the effects of training being lost, as muscle and fat will be used as energy sources
- Restricted energy intake may compromise and athlete's ability to obtain necessary nutrients
- Athletes need to consume enough energy to cover the energy costs of:
- daily living
- their sport
- building and repairing muscle tissue
- Energy balance = Ein = Eout
- Ein = energy consumed
- Eout = expended energy
- Energy balance is a dynamic process
- for example, if energy intake is changed through a different diet, this can affect the physiological and biological components of energy expenditure
- Influencing factors of energy balance can be:
- internal
- genetic
- epigenetic
- metabolic
- hormonal
- neural
- external
- environmental
- social
- behavioural
- internal
Energy intake | Energy expenditure |
---|---|
|
|
Training Consequences of a Negative Energy Balance[edit | edit source]
find references
- Increased risk of stress fractures
- Decreased athletic performance
- Slower phospocreatine recovery rates
- Athlete enters a hypometabolic catabolic state (low insulin growth factors, high cortisol-releasing hormone, high cortisol levels) and this hinders the addition of lean muscle mass
- Increased risk of injury
- Decreased metabolic rate
- Breakdown of lean tissue
How Many Calories do Athletes Need?[edit | edit source]
- TEE = REE x AL x TAE (ref)
- TEE = Total energy expenditure
- REE = Resting energy expenditure
- AL = Active lifestyle
- TAE = Training activity energy
- Adequate calories are a vital component of nutrition for athletes
- Quality is just as important as quantity (what you eat is just as important as how much you eat) (YOUTUBE VIDEO REFERENCE)
Carbohydrate Intake and Needs for Athletes[edit | edit source]
Carbohydrates for athletes:
- Provide energy
- Contributes:
- dietary fibre
- Vitamins for example vitamin B complex
- Antioxidants in fruits and vegetables
Considerations when discussing carbohydrates with athletes:
- quality of carbohydrates (low versus high quality)
- High versus low glycaemic index
- Timing of intake
- Variety of sources necessary
- vegetables, fruits, sweet potatoes, quinoa, brown rice, wild rice, nuts, seeds
How Much Carbohydrates[edit | edit source]
- Carbohydrate intake ranges from 3 to 10 g/kg BW/day (it may reach 12g/kg BW/day for extreme and prolonged activities)
- Intake ranges are dependent on:
- fuel demands of training and competition
- balance between performance and training adaptation goals
- total energy requirement of the athlete
- body composition goals of athlete
Activity Level | Carbohydrate targets |
---|---|
Light (low intensity exercise or skill-based training activities) | 3 - 5 g/kg of athlete's BW/day |
Moderate (Moderate training/exercise for about an hour/day | 5 - 7 g/kg of athlete's BW/day |
High (endurance training programme, 1 to 3 hours/day, moderate to high intensity exercise) | 6 - 10 g/kg of athlete's BW/day |
Very high (extreme training, more than 4 to g hours/day moderate to high intensity exercise) | 8 - 12 g/kg of athlete's BW/day |
Timing and Glycemic Index of Carbohydrates[edit | edit source]
- More carbohydrates on game days and days of intense training
- Fewer carbohydrates on off days and recovery days
- Fewer carbohydrates means that the athlete eats more vegetables, leafy greens
- Lower glycaemic index carbohydrates on non-training days
Fat Intake and Needs for Athletes[edit | edit source]
- Healthy diets do include fat as a component
- Fat provides energy
- Fat is an essential component of cell membranes
- Fat facilitates the absorption of fat-soluble vitamins
- Fat aids in recovery
- Growth hormone
- Testosterone levels in athletes
- Fat helps with:
- nervous system repair
- cognitive function
- decreases body inflammation
- Considerations with fat intake:
- omega 6: omega 3 ratio
- essential fatty acids
- fish oil fats (omega-3's)
- avoid trans fats
How Much Fat?[edit | edit source]
- Fat intake should not be less than 20% of an athlete's daily caloric intake
- Typically between 20% to 35% of total energy intake is acceptable
- Recommended: 0.5 to 1.0 g/kg of athlete's BW/day
Protein Intake and Needs for Athletes[edit | edit source]
- Athletes need more protein than the recommended daily allowance (RDA)
- Recommendations typically range from 1.2 to 2.0 g/kg of athlete's BW/day
- Endurance athletes need 1.2 to 1.7 g/kg of athlete's BW/day
- Strength training athletes need 1.6 - 2.2 g/kg of athlete's BW/day
- Vegetarians need more protein
- Benefits of protein intake at higher levels :find reference
- decreased blood tryglyceride levels
- improved body composition
- enhanced weight loss
- stabilised blood glucose levels
- reduced risk of disease
- improved bone health
Timing and Protein Intake[edit | edit source]
- Must have protein with every meal to help with muscle recovery and muscle protein synthesis
- Regular spacing of intakes of modest amounts of protein after exercise and throughout the day is recommended
Water[edit | edit source]
- Euhydrated = when an individual has normal body water content[15]
- Hypohydrated = when an individual has lower than normal body water content[15]
Hydration Goals for Athletes[edit | edit source]
- Begin exercise in a euhydrated state[16]
- Prevent excessive hypohydration during exercise[16]
- Replace fluid losses following exercise prior to the next training session/exercise bout[16]
- Avoid exercise associated hyponatremia[17]
- Read more: Fluid Excess/Intoxication
Fluid needs for athletes are individualistic and are reliant on factors such as[16]:
- sweat rate of the individual
- type of exercise
- exercise intensity
- environmental conditions
- duration of exercise
Dehydration has a negative impact on physical performance for activities that last more than 30 seconds, but it has no significant impact on performance for activities that last less than 15 seconds.[18]
American College of Sports Medicine (ACSM) Current Recommendations on Hydration[19]:
- Before exercise:
- 5 - 10 ml/kg BW water, 2 - 4 hours before exercise
- During exercise:
- 0.4 - 0.8 l/h during exercise
- After exercise:
- 1.25 - 1.5 l for every kg BW lost
Post-Workout Nutrition[edit | edit source]
Athletes can apply different strategies for recovery after exercise. The amount, consumption and timing of nutritional strategies differ according to factors such as[20]:
- the type of sport
- the time between training sessions
- the athlete's level of preparation
- the convenience of the specific nutritional strategy
The 4R's is a useful mnemonic to consider[20]:
- Rehydrate
- enough water to compensate for weight loss during training (1.25 - 1.5 litres for every kg BW lost)
- Refuel
- combination of carbohydrates and protein is a good strategy for glycogen replenishment and tissue repair
- Repair
- ingestion of high quality protein can contribute to faster tissue growth and repair
- Rest
- optimal sleeping time and good quality sleep is necessary for recovery
References[edit | edit source]
- ↑ 1.0 1.1 Costa-Pinto R, Gantner D. Macronutrients, minerals, vitamins and energy. Anaesthesia & Intensive Care Medicine. 2020 Mar 1;21(3):157-61.
- ↑ Slavin J, Carlson J. Carbohydrates. Advances in nutrition. 2014 Nov;5(6):760.
- ↑ Nimgampalle M, Chakravarthy H, Devanathan V. Glucose metabolism in the brain: An update. InRecent Developments in Applied Microbiology and Biochemistry 2021 Jan 1 (pp. 77-88). Academic Press.
- ↑ Blaak EE, Riccardi G, Cho L. Carbohydrates: Separating fact from fiction. Atherosclerosis. 2021 Jul 1;328:114-23.
- ↑ 5.0 5.1 Whitford D. Proteins: structure and function. John Wiley & Sons; 2013 Apr 25.
- ↑ Roefs MT, Sluijter JP, Vader P. Extracellular vesicle-associated proteins in tissue repair. Trends in cell biology. 2020 Dec 1;30(12):990-1013.
- ↑ Bellelli A, Tame JR. Hemoglobin allostery and pharmacology. Molecular Aspects of Medicine. 2022 Apr 1;84:101037.
- ↑ Muscella A, Stefàno E, Lunetti P, Capobianco L, Marsigliante S. The regulation of fat metabolism during aerobic exercise. Biomolecules. 2020 Dec 21;10(12):1699.
- ↑ Mohajan D, Mohajan HK. A Study on Body Fat Percentage for Physical Fitness and Prevention of Obesity: A Two Compartment Model. Journal of Innovations in Medical Research. 2023 Apr 21;2(4):1-0.
- ↑ Yildiran H, Macit MS, Özata Uyar G. New approach to peripheral nerve injury: nutritional therapy. Nutritional neuroscience. 2020 Oct 2;23(10):744-55.
- ↑ Meijaard E, Abrams JF, Slavin JL, Sheil D. Dietary fats, human nutrition and the environment: Balance and sustainability. Frontiers in Nutrition. 2022 Apr 25;9:878644.
- ↑ 12.0 12.1 12.2 12.3 Beck KL, von Hurst PR, O'Brien WJ, Badenhorst CE. Micronutrients and athletic performance: A review. Food and Chemical Toxicology. 2021 Dec 1;158:112618.
- ↑ 13.0 13.1 13.2 Godswill AG, Somtochukwu IV, Ikechukwu AO, Kate EC. Health benefits of micronutrients (vitamins and minerals) and their associated deficiency diseases: A systematic review. International Journal of Food Sciences. 2020 Jan 7;3(1):1-32.
- ↑ Alwis US, Haddad R, Monaghan TF, Abrams P, Dmochowski R, Bower W, Wein AJ, Roggeman S, Weiss JP, Mourad S, Delanghe J. Impact of food and drinks on urine production: A systematic review. International Journal of Clinical Practice. 2020 Sep;74(9):e13539.
- ↑ 15.0 15.1 Barley OR, Chapman DW, Abbiss CR. Reviewing the current methods of assessing hydration in athletes. Journal of the International Society of Sports Nutrition. 2020 Dec;17:1-3.
- ↑ 16.0 16.1 16.2 16.3 Belval LN, Hosokawa Y, Casa DJ, Adams WM, Armstrong LE, Baker LB, Burke L, Cheuvront S, Chiampas G, González-Alonso J, Huggins RA. Practical hydration solutions for sports. Nutrients. 2019 Jul 9;11(7):1550.
- ↑ Seal AD, Kavouras SA. A review of risk factors and prevention strategies for exercise associated hyponatremia. Autonomic Neuroscience. 2022 Mar 1;238:102930.
- ↑ Carlton A, Orr RM. The effects of fluid loss on physical performance: A critical review. Journal of Sport and Health Science. 2015 Dec 1;4(4):357-63.
- ↑ Thomas DT, Erdman KA, Burke LM. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: nutrition and athletic performance. Journal of the Academy of Nutrition and Dietetics. 2016 Mar 1;116(3):501-28.
- ↑ 20.0 20.1 Bonilla DA, Pérez-Idárraga A, Odriozola-Martínez A, Kreider RB. The 4R’s framework of nutritional strategies for post-exercise recovery: A review with emphasis on new generation of carbohydrates. International journal of environmental research and public health. 2021 Jan;18(1):103.