Chapter 13 - Performance enhancement and recovery strategies: psychological, nutritional & hydration Flashcards
U4 AOS2
13.1 - Nutritional needs of athletes: a balanced diet
Balanced diet
The appropriate balance of nutrients needed to supply the body w/ energy for physical activity & to aid in the recovery after exercise
* supplies energy
* nutrition & hydration are key to optimal performance
* important through choice of fod, timing & quantitiy
* essential nutrients:
- CHO
- fats
- protein
- vitamins
- minerals
- water
- fibre
13.1 - Nutritional needs of athletes: a balanced diet
Balanced diet
Considerations
- specific nutritional requirements of sport
- individual energy expenditure
- individual metabolism
- state of health
13.1 - Nutritional needs of athletes: a balanced diet
Balanced diet
Pre-training/comp
During-training/comp
Post-training/comp
Pre: aims to keep athlete from feeling hungry before & during exercise, & maintain optimum levels of energy stores for the following activity
During: acts as an alternative fuel source & maintains fluid lost through exercise bout.
- beneficial for events longer than 30min
Post: ingested in a timely manner, aims to optimise recovery following the exercise session
13.2 - Nutritional needs of athletes: CHO
CHO
Functions:
* major energy fuel source for high-intensity activity
* regulate metabolism of fat & protein
* nervous system relies on them for energy to function
* broken down in glycogen & stored in the liver & muscles
* transported into the bloodstream in form of glucose
13.2 - Nutritional needs of athletes: CHO
How much CHO
- excess beyond what liver & muscles can store becomes fat
- amount of CHO consumed impacts amount of muscle glycogen available for activity
- most imprant factor is the number of ingested grams
- 7-10g of CHO per kg body mass
- needs are dependent of type of training/competition - frequency, duration & intensity
13.2 - Nutritional needs of athletes: CHO
Glycaemic index
A scale that ranks CHOs by how much they raise blood-glucose levels over 2hr compared to pure glucose
* allows for determination of what CHOs to eat & when
* manipulated to enable optimal CHO availabiliy - enhances performance & recovery
13.2 - Nutritional needs of athletes: CHO
CHO nutitional classifications
Nutrient-dense CHO
Foods and fluids that are rich sources of other nutrients including protein, vitamins, minerals, fibre and antioxidants in addition to CHO
- Breads and cereals
- Fruit
Everyday food that should form the base of an athlete’s diet.
Helps to meet other nutrient targets
Nutrient-poor CHO
Foods and fluids that contain CHO but minimal or no other nutrients
- Lollies
- CHO gels
- Sports drinks
Shouldn’t be a major part of the everyday diet but may provide a compact CHO around training
High-fat CHO
Foods that contain CHO but are high in fat
- Pastries
- Cakes
- Chips
- chocolate
‘sometimes’ foods best not consumed around training sessions
13.2 - Nutritional needs of athletes: CHO
Rebound hypoglycaemia
Low blood glucose follwied by a rapid rise of blood glucose
* rise will supress the use of fats as an energy supply - muscle relies more on CHO
* results in a drop in blood glucose levels in inital stages of exercise
* low Gi foods should be consumed during pre-event meal
13.2 - Nutritional needs of athletes: CHO
CHO meals
Pre exercise
During exercise
After exercise
Pre: provide oppurtuity for athletes competing in loger endurance events (>90min) to increase fuel storgae
During: CHO should be consumer regularly to enhance endurance & performance.High GI food are recommended & therefore are more readily available got an immediate energy source
After: consits of high GI foof to promote muscle glycogen resynthesis
13.2 - Nutritional needs of athletes: CHO
Benefits of low GI foods
in general terms daily nutritional choices should shift towards low GI foods. benefits include:
* lowered lipid (fat) levels in blood
* assistamce in weight control
* decreased risk of heart disease
* decreased risk of diabetes
- personal factors have an influence on nutritional choices
13.2 - Nutritional needs of athletes: CHO
CHO gels
- concentrated CHO
- to be effective they should be consumed w/ water
- provides similar benefits to sports drinks
- shouldn’t be taken w/ sports bars when high sweat rates occur - increase in CHO concenration & resultant slowing of hydratioj rates
- supplements CHO supply for muscular activity
- an immediate fuel source directly from bloodstream to resynthesise ATP
13.2 - Nutritional needs of athletes: CHO
CHO gels
Situations
- Compact fuel source for endurance athletes during exercise lasting longer than 90 min - especially where it is impractical to carry large amounts of sports drinks (i.e. cyclists)
- Compact fuel source for team sports athletes during breaks in play during extended training or competition sessions
- Compact &portable source of CHO for post-exercise recovery when regular foods aren’t tolerated
- Low-fibre & compact pre-event snack for athletes unable to tolerate regular foods & fluids
13.2 - Nutritional needs of athletes: CHO
CHO gels
Concerns
- Gastrointestinal intolerance may occur due to concentrated CHO load
- Sports gels should always be consumed with adequate fluid to meet hydration needs
- Athletes should practise use of gels & assess tolerance during training sessions if they are intended for use during competition
- Gels may lead to over-consumption & over-reliance on low-nutrient CHO sources
Gels are an expensive alternative to regular food & fluid choices - supplement should only be used for specific conditions for which its suited
13.3 - Nutritional needs of athletes: proteins
Protein
Functions:
- muscle construction & repair
- promoting glycogen resynthesis
- plays an important role in the immune system
- facilitates the transmission of nerve impulses throughout the nervous system
- preventing sports anaermia by promotion an increased synthesis of haemoglobin, myoglobin & oxidative enzymes
- broken down through digestion into amino acids:
- essential amino acids: cant be made by the body, so must be consumed.
- non-essential amino acids: can be made from other amino acids in the body.
13.3 - Nutritional needs of athletes: proteins
Protein
Structural protein
Regulatory protein
proteins can be classified as:
- structural proteins: build connective tissue, cell membranes & muscle cells
- regulatory proteins: act as enzymes or transported vehicles.
13.3 - Nutritional needs of athletes: proteins
How much protein
- protein plays a key role in post-exercise recovery & repair
- should be 15% of daily intake - strength & endurance athletes require more for growth of muscle tissue
- guideline of 1-2g/kg of BM
- after intense exercise muscle protein is broken down due to catabolic microtrauma from exercise demands
- protein consumption immediately after is essential to reverse the negative protein balance
13.3 - Nutritional needs of athletes: proteins
Protein and CHO
- when consumed together they stimulate a greater release of insulin - enhance amino acid uptake & promote glucose delivery to depleted muscle cells
- 1:4 ratio of protein to CHO for glycogen replinishment immediately
- insulin stimulates protein synthesis & helps to reduce protein breakdown & enhance skeletal muscle protein
13.3 - Nutritional needs of athletes: proteins
Protein supplementation
- protein powders made into shakes or bars
- excess protein can’t be stored - broken down & excreted
- large quantities can place strain on kidney
13.4 - Nutritional recovery in relation to the type of sport or activity
Nutritional recovery
- due to frequency of training each meal must be considered carefully so all nutritional requirements are met
- need to avoid chronic CHO depletion - impairs training adaptations & competition performance
- need to acheive optimal work & avoid fatigue from inadequate nutrition
13.4 - Nutritional recovery in relation to the type of sport or activity
Factors causing nutrition-related fatigue
- depletion of glycogen stores
- hypoglycaemia
- dehydration
- low blood sodium levels
- gastrointestinal upset
13.4 - Nutritional recovery in relation to the type of sport or activity
Nutritional prep for shorter-duration sports
- fatigue isn’t caused by glycogen depletion in high-intensity sports under 60min
- fuelling during events 30min+ can be beneficial - provides brain w/ feed-forward mechanism to increase rate of neural firing, aids in maintaining intensity & preventing fatigue
- fluid replacement should match fluid loss - main focus
- water is adequate in short-duration activities
13.4 - Nutritional recovery in relation to the type of sport or activity
Nutritional preperations for moderate intensity/intermitten sports
- sports lasting 60-90min can be fuelled bu ‘normal’ glycogen stores in well-trained athletes
13.4 - Nutritional recovery in relation to the type of sport or activity
Nutritional prep for prolonged submaximal events
- atheltes in events 90min+ should consume additional CHO before event (CHO loading)
CHO loading: involves the manipulation of training & nutrition prior to endurance events to maximise muscle glycogen (CHO) stores - increases muscle stores by 50-100%
- should happen 4-8hr before event
- aerobic endurance training trains muscles to store greater amounts of glycogen & use it sparingly
- during event consumption pf 30-60gCHO/hr & fluid replacement is needed
13.4 - Nutritional recovery in relation to the type of sport or activity
Fuelling during exercise
- sports less than 90min can be adequately fuelled from stored CHO & fat w/o replinishment
- sports longer than 90min benefit from high GI foods - keeps blood-glucose in normal range, provides extra immediate fuel sources & delays fatigue
- start refuelling early in event having 30-60g CHO with a high GI per hour
- examples of 60g:
- 2 large bananas
- 1.5 sports bars
- 95g of jelly beans
- 1 jam sandwhich
Carbohydration: the combination of hydration w/ the replenishing of CHO lost during activity, in order to avoid dehydration - should replace fluids at 500-1,000mL of fluid/hr
13.4 - Nutritional recovery in relation to the type of sport or activity
Nutrition & recovery from exercise
- must restore glycogen & rehydrate asap - immediately after when glycogen synthesis is greatest
- proper ratio of nutrients enhances rebuilding of catabilic mudvlr microtrauma & resotores energy reserves
- should consume CHO rich foods/drinks providing 1-1.5g CHO/kgBM within 30min
- initial couple hrs muscles are more receptive to restoring greater amounts of CHO
*
13.4 - Nutritional recovery in relation to the type of sport or activity
Nutrition & recovery from exercise
Main considerations
- consuming high GI foods allows for a faster absorption & resynthesis of glycogen in muscle & liver
- consumption should occur in first 30-60min when muscles are most receptive to converting glucose to glycogen
- a high CHO diet should be maintained for 4-6hrs
- consumption of CHO & protein post-exercise enhances recovery process
- appropriate post-exercise nutiotion will support the immune system
13.4 - Nutritional recovery in relation to the type of sport or activity
Combining CHO & protein for enhanced recovery
- CHO & protein work in synergy to enhance recovery
- stimulate insulin production - a powerful anabolic hormone to increase uptake of amino acids and enhance muscular recovery & growth
- combo of high GI foods & fast-digesting (whey) protein is the best recovery combo
13.4 - Nutritional recovery in relation to the type of sport or activity
Recovery nutrition to support the immune system
- intense training supress the immune system & continues in the hrs following
- athletes are more suspectible to illness
- adequate consumption of Vitamin C & E, glutamine, zinc & probiotics reduce risk
- consumption of adequate CHO before, during & after prolonged or high-intensity exercise reduces susceptibility
- CHO reduce stress hormone response & supplies fuel to WBC
13.5 - Hydration needs of athletes
Hydration
- the body needs to replace about 2L of fluid lost daily
- fluid has many functions:
- to transport energy, waste, hormones & antibodies
- dilute waste products
- lubricate surfaces & membranes
- to help regulate body temp
- to be involved in all chemical reactions in the body