Case Study Nutrition
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Transcript of Case Study Nutrition
INTRODUCTION
The field of sports nutrition is constantly changing and evolving. Today, more than ever,
athletes and strength and conditioning coaches maximize the practice of ingesting the proper
nutrients, in the correct amounts, at the proper time to improve performance. The impact of
scientific research regarding nutrition cannot be overlooked; there are thousands of studies on
proper nutrient intake and its effect on performance. Proper nutrition is an important
consideration for athletes who seek to maximize performance. No diet directly increases
strength, power, or aerobic endurance, but an adequate diet allows athletes to train and
compete to the best of their ability. The physiological needs of competitive athletes often
require diets that are quite different from a sedentary individual’s diet. The ideal diet for an
athlete depends upon many different factors including age, body size, gender, genetics, and
environmental training conditions, as well as training duration, frequency, and intensity.
Therefore, requirements vary greatly between, as well as within, different athletic groups and
the best diet for any given athlete is one that is individualized for that specific athlete.
Undertaking physical activity alters a person’s need for energy, nutrients and fluids.
By understanding the dietary needs of athletes and planning eating strategies for before,
during and after activity, individuals can enhance their recovery and maximise physiological
responses from training, as well as improve their performance. Other strategies can also be
employed to assist with recovery so that individuals can be at peak performance during the
next event.
1) PARTICULAR ATHLETE FROM THESE EVENT
Combined Power and Endurance Sport (Intermittent Spor
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2) ATHLETE BIOGRAPHY
Name’s : Mohamad Hamka Nizam Bin Mohamad Rosni
Sport Participate’s : Rugby
Weight : 70 Kg
Height : 162 Cm
Age : 25 Years Old
Practices/Training Sessions : Depends on Coach
* 1 Month = Centre Training
* Minimum Training = 2 Weeks
* Maximum Training = 5-6 weeks
Dietary Patterns :-
* Before Training : Consume a banana fruits and energy drinks
* After Training : Consume energy drinks for recovery
* 1 Hour After Training : Consume heavy meals such as rice, fried chicken
Supplements Intake :-Whey Protein
* Consume 2 times per day
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3) PLAN AN IDEAL DIET FOR CLIENT IN PREPARATION FOR THE
COMPETITION AND RECOVERY
Type of food and drink the athlete will be consuming
~ Carbohydrate foods and milk shake or liquid meal supplement
The amount of food (kcal) and drink (ml) consumed
During Training Sessions (Pre and Post Training)
~ The training diet must provide adequate carbohydrate to meet the fuel
demands of training, contain a moderate amount of protein and be low in fat.
Community nutrition guidelines express goals for macronutrient intake in
terms of the percentage of total energy they should provide. It is best, however,
to set definite carbohydrate and protein intake goals for athletes, scaled to their
body size and, therefore, their muscle mass and training demands. This is
achieved by stating their requirements in grams per kilogram of body mass.
~ One important factor to consider when determining recommendation’s for
carbohydrate intake is the training program. More recently, research has shown
that athletes engaging in high-intensity, intermittent activities also benefit from
high-carbohydrate diets. The glycemic index of a carbohydrate source describe
the rate at which glucose levels rise in the blood following consumption of 50 g
of food. The glycemic score for a food is largely determined by the rate at
which ingested of carbohydrates are available to enzymes in the small intestine
for hydrolysis and subsequent absorption.
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Carbohydrate
Carbohydrate is stored as glycogen in the body, more specifically in skeletal
muscles and the liver. Muscle stores of glycogen are an energy source for
training and competition, and the availability of carbohydrate plays a key role
in the performance of moderate to high-intensity exercise lasting an hour or
more. Depending on an athlete’s muscle mass, nutritional state and training
status, the level of glycogen stored in muscle is highly variable. Relative to fat,
however, the body can store only a small amount of carbohydrate. It is
important then that carbohydrates form the basis of each meal and ‘in-between’
snack to ‘top up’ energy stores in muscles for exercise.
Compromised or reduced stores of glycogen may lead to early fatigue,
loss of concentration and slower recovery after exercise. For activities of short
duration involving intense anaerobic work the most important fuel used for
energy is muscle glycogen. As this supply declines with prolonged exercise,
blood glucose is utilised as a carbohydrate fuel source. The majority of
carbohydrates consumed in an athlete’s diet should be from nutritious sources,
with refined carbohydrates only providing extra kilojoules where required.
The following foods are nutritious carbohydrates that provide energy as well as
a good source of vitamins, minerals, antioxidants and fibre.
Examples of Training Diet Meals of Carbohydrate :-
1) Bread
2) Cereal (including wheat biscuits, ‘flake cereals’, porridge and muesli)
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3) Pasta (including spaghetti, fettuccine, tagliatelle and ravioli)
4) Rice (including white, brown and wild rice)
5) Potato (including mashed, boiled, baked and in jackets), sweet potato and
corn
6) Fruit (including fresh, canned, stewed, dried and fruit juice)
low-fat dairy products (including plain milk, flavoured milk, yoghurt and
custard)
In addition to the above, but not in place of them, foods containing
refined carbohydrates may be included to ‘top up’ total energy intake where
required or provide an easy-to-digest form of carbohydrate in and around
training and competition. These include honey, jam, sugar, jelly, soft drinks
and sports drinks.
CHO = carbohydrate; BM = body mass
(Current Concepts in Sports Nutrition, Australian Institute of Sport)
Table 1 Daily Carbohydrate Requirements
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Figure 1 Carbohydrates provide fuel for muscle and are a good source of vitamins and minerals
Protein
Proteins are made of various combinations of more than 20 amino acids. Nine
of these amino acids are called ‘essential’ amino acids because they cannot be
manufactured by the body and must be supplied from the diet. The major
function of amino acids is to make and repair the cells of the body and
manufacture enzymes and hormones. The body breaks down food into amino
acids from which it then makes its own protein as required. Another function of
protein is to provide energy in extreme conditions, such as starvation.
An athlete requires a slightly higher protein intake than does the
average person, but this can easily be met if the athlete’s overall energy intake
is adequate. Amino acids are critical for growth and repair so many athletes
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attempt to increase their protein intake to improve muscle repair and increase
their size. Large quantities of protein are not required to increase muscle mass.
In fact, if protein intake is increased at the expense of carbohydrates, the
opposite can occur; that is, muscle can be broken down to provide energy for
work. Excessive protein intake can also dampen an athlete’s appetite and may
restrict his or her capacity to meet total energy needs.
If the protein intake of an athlete is insufficient it can lead to early
fatigue, inability to build and/or maintain muscle and slow recovery from
injury. The recommended daily intake (RDI) of protein for active people is
0.8–1.2 grams of protein per 1 kilogram of body mass. Both for endurance
athletes and those undertaking heavy resistance training, this can be increased
to 1.6 grams per 1 kilogram of body mass. Protein intake in excess of these
limits is generally utilised as a fuel source rather than for production of the
various body proteins.
Examples of Training Diet Meals of Protein :-
1) Lean meat (including beef, lamb and veal)
2) Poultry (including chicken, turkey and eggs)
3) Fish (including fresh and canned)
4) Low-fat dairy products (including milk, yoghurt and cheese)
5) Legumes (such as lentils and baked beans) and nuts.
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*Exercising approximately four to five times per week for 45–60 min + Exercising four to five times per week for 30 min at <55% VO2 peak
(Burke and Deakin, Clinical Sports Nutrition, 3rd edn, McGraw-Hill Australia, 2006)
Table 2 Estimated Protein Requirements for Athletes
Figure 2 Good sources of protein; dairy, nuts and legumes also provide protein
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Fat
Fat is mobilised as an energy source when the activity is of low intensity and
more aerobic and longer in nature. Fat supplies twice the kilojoules as the same
amount of carbohydrate and protein, but as an energy source it is not as
efficient as carbohydrate.
Excess fat in the diet can lead to the storage of extra body fat and can
also cause insufficient carbohydrate intake. This can result in decreased
endurance, speed, agility and flexibility. A small amount of dietary fat is
needed for normal body functions and there may be times where extra fat can
be included in the diet to boost total energy intake (such as for a growing
athlete who is struggling to eat enough). All athletes, no matter how lean,
should manage their fat intake to allow room for more good quality
carbohydrate and protein sources in their diet and prioritise the foods important
for maximising performance.
Examples of Training Diet Meals of Fat :-
1) Butter, cream and full-cream dairy products
2) Animal fat (on meat)
3) Cakes, pastries and sweet biscuits
4) Chocolate.
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Figure 3 Some examples of fats to avoid or limit to maximise performance
Fluid
Hydration is important for optimal exercise performance. The loss of excess
fluid from the body via sweat can result in reduced exercise performance,
fatigue, a higher heart rate and the potential for greater heat stress during
exercise. Dehydration can also cause headaches and disruption to the ability to
digest food and fluids during exercise. Starting every exercise session in a
well-hydrated state is important for optimising performance. A ‘pale straw’
urine colour is indicative that an individual is well hydrated and this is
therefore the goal for athletes throughout most of the day; a darker urine colour
indicates dehydration. Note: Some medications and multivitamin and mineral
supplements can darken the colour of a person’s urine, which can make
tracking hydration status inaccurate via the colour method.
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Sweat rates differ enormously between individuals, which makes it very
difficult to set general fluid intake guidelines. It is important for athletes to
become familiar with their own sweat rates during exercise. This can be done
by weighing before and after an exercise session. The amount of weight lost in
kilograms is equivalent to the amount of fluid lost in litres. Athletes should
drink enough fluid during exercise to minimise this weight loss to under 1
kilogram, where possible. Such measures help to set up individualised fluid
intake plans based on the rate of sweat loss over a session. This also helps to
reduce the risk of hyponatraemia, a dangerous condition caused by drinking
excessive amounts of fluid (that is, the athlete should not drink so much that he
or she gains weight during exercise).
Water, juice, cordial, tea, coffee and milk are all useful sources of fluid
(and hence for maintaining hydration) throughout the day. Athletes should be
aware that some of these sources of fluid also contain calories and are therefore
not necessarily the best option for ‘quenching thirst’.
During Competition (Pre and Post Competition)
As carbohydrate is the primary fuel source for exercise of moderate to high
intensity, optimising carbohydrate status in the muscle and liver is the primary
goal of competition preparation. The length of time dedicated to pre-event
fuelling will depend on the balance between the anticipated fuel needs of the
event and the preparation time that can be dedicated to the event.
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For events lasting no longer than 60–90 minutes, athletes can usually ensure
adequate glycogen stores for their event by resting or undertaking light activity
for the 24–36 hours after their last training session, while consuming 5–7
grams of carbohydrate per 1 kilogram of body mass. To that end, carbohydrate-
rich foods should form the basis of every meal and snack in the one to two days
before competition.
For most events lasting longer than 90–120 minutes, which would
otherwise be limited by depletion of glycogen stores, athletes may benefit from
undertaking carbohydrate loading. This is a strategy involving changes to
training and nutrition that can maximise muscle glycogen stores prior to
endurance competition. The technique originally involved a three-day to four-
day carbohydrate ‘depletion phase’ and a three-day to four-day ‘loading
phase’. Ongoing research has demonstrated that the depletion phase is no
longer necessary and it is now thought that a two-day high-carbohydrate diet
(10–12 grams of carbohydrate per 1 kilogram of body mass) combined with an
exercise taper is sufficient to elevate muscle glycogen levels. It has been
demonstrated that this extra supply of carbohydrate improves endurance
exercise by allowing athletes to exercise at their optimal pace for a longer time.
Pre-performance meal
The goals of the pre-event meal are to:
1) Top up glycogen stores in muscle and the liver (especially after an
overnight fast)
2) To ensure an adequate level of hydration
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3) To prevent hunger
4) To assist in the psychological preparation of the athlete through routine or
ritual.
As food consumed before exercise is only useful once it has been
digested and absorbed, athletes are encouraged to consume this meal within the
four hours prior to their competition. The pre-performance meal should be a
carbohydrate-rich meal that the athlete has consumed before. The meal should
also be low in fat and fibre and moderate in protein as these nutrients will take
longer to digest and may increase the risk of stomach discomfort during
exercise. Athletes should experiment to find the timing that best suits their
needs.
Generally, tolerance of food and fluid is better during lower-intensity
activities or sports where the body is supported (such as swimming and
cycling) compared with sports such as running where the gut is jostled about
during exercise. A general guide is to have a meal about three to four hours
before exercise or a lighter snack about one to two hours before exercise.
Including fluids with the pre-event meal will help athletes optimise their
hydration status. The amount needed will differ between individuals and must
take into consideration the conditions under which the exercise is to be
conducted.
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The following foods are examples of what may be suitable to eat 3–4
hours before exercise:
1) Pancakes
2) Breakfast cereal with milk
3) A bread roll with a cheese or meat filling and a banana
4) Fruit salad with fruit-flavoured yoghurt •
5) Pasta or rice with a sauce based on low-fat ingredients • (such as tomato,
vegetables, lean meat).
The following snacks are examples of what may be suitable to eat 1–2
hours before exercise:
1) toast or crumpets with jam or honey
2) a liquid meal supplement
3) a sport or cereal bar
4) a piece of fruit.
Nutrition during performance
The goal of nutrition intake during exercise is to minimise the fluid deficit and,
in the case of exercise of moderate to high intensity lasting longer than 60
minutes, provide an additional fuel source for the muscles and central nervous
system.
Intake of carbohydrate during exercise provides an additional fuel
source and has the potential to improve exercise capacity in situations where
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muscle or liver glycogen stores may limit performance. While most evidence
for the benefits of carbohydrate supplementation during exercise has been
described for prolonged bouts of moderate-intensity exercise, there is
increasing evidence that it may also be of benefit to athletes competing in
individual or team-based sports of an intermittent nature lasting greater than 60
minutes.
The amount of carbohydrate that athletes can consume will represent a
compromise between what is ideal, the opportunities to consume foods/fluids
during the event and the tolerance of athletes while exercising. For example,
the ability of a road cyclist or tennis player to consume fluids during an event
will generally be greater than that of a marathon runner. Depending on the
nature of the event, suitable carbohydrate-rich food and fluid options may
include bananas, sports gels/bars and sports drinks. The latter has the
advantage of helping the athlete meet his or her fuel and fluid demands
simultaneously.
Dehydration to the extent of just 2 per cent of an athlete’s starting body
weight can have detrimental effects on performance, which include:
1) reduced aerobic performance
2) increased perceived exertion - causing the athlete to feel more fatigued
than usual at a given work rate
3) reduced mental function - having a negative impact on motor control
(skill), decision-making and concentration
4) slowed gastric emptying - resulting in stomach discomfort.
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It is therefore important that athletes aim to start each competition or
training session well hydrated and minimise the fluid deficit during exercise.
Fluid requirements vary remarkably between athletes and between exercise
situations. This makes it impossible to prescribe a general fluid-replacement
plan. Athletes should be encouraged to look for opportunities to consume fluids
during their sport, and aim to start drinking early and continue to drink small
amounts regularly. Ideally, athletes should drink to a plan based on their own
sweat rates during training and competition. While water is always a good fluid
to choose, sports drinks can have the advantage of supplying carbohydrate
during the event, as well as sodium to help in the absorption of the fluid into
the body. This is especially important in events undertaken in the heat or where
fuel supply and dehydration can limit performance.
Post-performance / recovery nutrition
Recovery is a challenge for athletes who are undertaking two or more sessions
each day, training for prolonged periods or competing in a program that
involves multiple events. In the training situation, with correct planning of the
workload and the recovery time, adaptation to the physiological stress allows
the body to become fitter, stronger and faster. In the competition scenario,
there may be less control over the work-to-recovery ratio.
Recovery encompasses a complex range of processes that include:
1) restoring the muscles and liver’s expended fuel
2) replacing the fluid and electrolytes lost in sweat
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3) manufacturing new muscle protein, red blood cells and other cellular
components as part of the repair and adaptation process
4) allowing the immune system to handle the damage and challenges caused by
the exercise bout.
How well athletes recover after a bout of exercise will have an impact
on their ability to perform in subsequent training and competition. The specific
food and fluid recovery strategies that athletes adopt will depend on the nature
of the training session or competition undertaken and the length of time before
the next session or event. From a nutrition standpoint, the goals of recovery are
as follows:
1) Refuel - carbohydrate (energy) stores.
2) Rehydrate - to replace fluids and electrolytes lost in sweat.
3) Repair - repair and regenerate damaged muscle tissue.
4) Revitalise - revitalise and maintain good immune function.
Refuel carbohydrate (energy) stores
Athletes should consume carbohydrate as soon as possible after an exhausting
work-out (ideally within 30 minutes), to prepare for the next. The carbohydrate
should be consumed either as part of their next meal or as a snack.
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Figure 4 Nutritious carbohydrate-protein recovery snacks
Rehydrate to replace fluids and electrolytes lost in sweat
Most athletes finish training or competition sessions with some level of fluid
deficit. Athletes should aim to replace 125-150 per cent of the fluid deficit
over the next 2-4 hours to fully replace the existing and ongoing fluid losses.
Repair and regenerate damaged muscle tissue
Prolonged and high-intensity exercise causes a substantial breakdown of
muscle protein. Dietary protein consumed immediately after a session is taken
up more effectively by the muscle into rebuilding processes than is protein
consumed in the hours afterwards. Protein should ideally be consumed with
carbohydrate-rich foods to maximise this effect. Optimal amounts of protein
are 10-20 grams.
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Revitalise and maintain good immune function
In general, the immune system is suppressed during the hours following
intensive training. Consuming carbohydrate during and/or after a prolonged or
high-intensity work-out has been shown to reduce the disturbance to immune
system markers. This may help reduce the risk of athletes catching an
infectious illness during this time.
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