Nutrition and Exercise

Question 1

What is ATP

Answer 1

A chemical compound called adenosine triphosphate produces energy for movement
ATP = energy
When energy is needed for a muscular contraction, one of the phosphate molecule breaks off, producing energy
Only a very small amount of ATP is stored within muscles, so ATP is continually restored to provide energy for longer periods
ATP can be rebuilt from the breakdown of phosphocreatine or macronutrient from our diet

Question 2

Fats

Answer 2

Fats are broken down into either fatty acids, which are found in the blood and adipose tissue, or triglycerides which are stored in the muscle
Represent the most plentiful source of potential energy and are the body’s primary source of fuel at rest or prolonged submaximal exercise

Question 3

Proteins

Answer 3

Protein makes a negligible contribution to energy production during exercise
An essential nutrient in the diet
is needed to
Build connective tissue and muscle cells
Acts as enzymes that speed up chemical reactions
Production of red blood cells, hormones and antibodies
Stored in muscles and around the body
Used mainly for growth and repair of muscles

Question 4

Carbohydrates

Answer 4

Broken down into glucose for blood transportation
Excess blood glucose is converted to glycogen and stored in the muscles and liver
When other stores are full, it is stored in adipose tissue
Carbs are the body’s preferred fuel choice, particularly through exercise

Question 5

Glycemic index

Answer 5

Ranks carbs based on their immediate effect on blood glucose (sugar) levels
Measure on a scale of 1 (low)-100 (high)
Low GI foods
○ Apples
○ Lentils
○ Beans
Medium GI foods
○ Corn
○ Peas
○ White pasta
High GI foods
○ Honey
○ White bread

Question 6

High GI foods

Answer 6

Break down quickly during digestion meaning they have an immediate effect on blood glucose levels
When should you have them?
Immediately before exercise (30 mins prior)
During exercise
Immediately after exercise (30 mins after)

Question 7

Low GI foods

Answer 7

Breaks down slowly during digestion meaning they have a slow release of glucose into the bloodstream
When should you have them?
Pre-event meal (1-4hrs prior)
After exercise (1-24hrs after)

Question 8

rebound hypoglycaemia

Answer 8

Athletes shouldn’t consume high GI foods 30-120 mins before the event as rebound hypoglycaemia may occur
Immediately after consuming carbs there is a rise in blood glucose levels, resulting in insulin being released to lower blood sugar levels
When athletes eat high GI foods before an event, the rapid release of blood sugar causes the release of insulin to overshoot
This significantly reduces blood sugar levels which causes a negative effect on performance

Question 9

ATP production during physical activity

Answer 9

Exercising at sub-maximal levels can be typically be met by the aerobics system as the body’s ability to utilise O2 can meet the muscles demand for extra O2 for greater
During high intensity exercise, the respiratory and circulatory systems are unable to supply the muscles cells with sufficient O2 to meet energy demands
Causes muscles to burn glucose anaerobically
Anaerobic systems can produce ATP very quickly, however the have disadvantages
Produce a limited amount
Produce fatiguing by-products

Question 10

Hitting the wall

Answer 10

the fuel source used for ATP production is based on the duration and intensity of the exercise
Low intensity/rest
As intensity of exercise increases, the contribution to muscle glycogen also increases to meet the demands of fuel
There is enough glycogen stored in muscles for about 60 minutes of exercise depending on the intensity
When muscle glycogen stores run out, the liver glycogen stores take over as primary fuel source allowing exercise to continue but with a diminished performance
Depletion of liver glycogen stores affects the brain meaning decision making is impaired
Fats now become the predominant fuel source, and the intensity of exercise is reduced as fats require more energy to digest
Depletion of fats means protein becomes the fuel source

Question 11

Carb loading

Answer 11

Carbohydrate loading is a nutritional intervention aimed at delaying the depletion of glycogen stores
It occurs when athletes increase carbs consumed prior to competition with the aim of storing extra glucose in the liver and muscles
3 day method
1 day method
Energy drinks are only beneficial for events longer than 1hr

Question 12

3 day method

Answer 12

Consume 7-8g/kg bodyweight in carbs each day for 3 days leading up to competition
Players can still exercise but significant tapering should occur leading up to competition

Question 13

1 day method

Answer 13

Consume 8-10g/kg bodyweight in carbs the day before the competition
Tapering is required to spare muscle glycogen stores

Question 14

advantages and disadvantages of carb loading

Answer 14

Advantages
Carb loading avoids the depletion of glycogen stores by increased the muscular and liver glycogen levels
Sparing glycogen allows aerobic athletes to maintain a higher intensity for longer

Disadvantages
Binding of H2O molecules increases H2O absorption, causing an increase in weight

Question 15

pre event meal

Answer 15

The aim is to provide adequate carbohydrates and to ensure optimal hydration levels leading into the event
Considerations
Food preference
Digestibility of foods
Advantages
Increase glycogen levels lead to glycogen sparing
Ensures optimal hydration
Ensures digestive tract feels comfortable during performance

What you should eat and when
1-4hrs prior to competition
Low GI foods
Wholemeal pasta, apple
Consume 600-800ml fluid an hour before

Question 16

during event meal

Answer 16

Sports lasting up to 60mins can be fuelled from carbs and fat
For sports longer than 60mins carbohydrate replenishment is important to avoid depletion of stored glycogen
Ingestion of carbs during the event prevents low blood sugar levels

What you should eat when
30-60g of high GI carbs per hour
200ml fluid every 15 minutes
Electrolyte drinks with 5-8% carb concentration
Avoid high fibre/fat foods as they are difficult to digest

Question 17

immediately post event meal

Answer 17

Immediately after the event muscles are most responsive to topping up glycogen stores
As a result, increase in muscle glycogen stores occurs due to the consumption of high GI foods
The more depleted the stores are of carbs, the faster the recovery rate

Question 18

post event meal

Answer 18

It takes at least 24 hours for glycogen replenishment after heavy endurance work
The amount of carb replenishment is dependent on the intensity and duration of exercise
Consume low/medium GI foods for the next 24hrs after completes the replenishment of glycogen store
Protein is important post exercise to ensure muscles repair in time for the next bout of exercise

What you should eat when
1g/kg bodyweight of high GI carbs within 30mins of event
At least 7-10g/kg bodyweight of low GI carbs over the next 24hrs
Consume fluid which equates to 1.5x fluid loss