Week 4 lectures- week 3 was videos week

Question 1

Nutrients definition

Answer 1

A substance found in the body that performs one or more specific functions within the body. Nutrients can be split into macro and micro nutrients- refers to how much need they are within the body.

Question 2

Do you need more macro or micro nutrients?

Answer 2

Macronutrients are needed in far larger quantities with micronutrients found in less than 1 gram per day. Nutrients are measured in per grams.

Question 3

What are the main macronutrients?

Answer 3

Carbs , proteins, fats and water

Question 4

What are the main micronutrients?

Answer 4

Vitamins, minerals and trace elements

Question 5

Nutrient function

Answer 5

Nutrients provide energy, regulates metabolism and promotes growth and development

Question 6

Gastrointestinal function and pathway

Answer 6

Helps get energy from our food into our body.

Gi tracts starts at the mouth and is mixed, chewed and swallowed. Then it travels down to the stomach where their is protein and fat digestion- food is also sterilized and a very acidic environment occurs. Stomach can work as a storage site for food to ensure intestines are not overwhelmed and chyme is emptied from the stomach to the small intestine. Small intestine is where main part of digestion occurs and further absorption to the body. 905 nutrients can be absorbed into the small intestine here. What is not absorbed there can be absorbed in the small intestine and is mainly water and minerals- and formation of faeces happens here.

Question 7

How can GI impair performance?

Answer 7

Through GI stress or discomfort

Question 8

Carbs sources, storage and function

Answer 8

Mainly found in plant based sources such as grains, potatoes, pasta and rice. Starch is the main storage form in plants.
Can also find carbs in sugar form in many sports nutrition products.
Carbs consumption helps make sure the body is repleted. Carb consumption isnt actually necessary and can produce carbs in the liver through gluconeogenesis.

Question 9

Essential nutrient definition

Answer 9

Essential nutrient is anything that the body cannot be produced and must be produced by the diet

Question 10

Fats function

Answer 10

They act as a fuel source, protect vital organs, act as cell membrane constituents, can be precursors of bile/hormones/steroids, palatability and fat soluble vitamin intake.

Question 11

Which vitamins are fat soluble?

Answer 11

Vitamins A, D, E, K- They are dissolved in fats so rely on dietary intake of fats to get into the body. So a low fat diet can lead to a deficiency in some nutrients.

Question 12

Where do proteins come from and what is their function?

Answer 12

Proteins (amino acids)- come from an array of plant and animal sources and can provide structure to cells within the human body. Many proteins are enzymes which play important roles in metabolic reactions and many organs and tissues metabolisms. Amino acids = precursors for the synthesis of body proteins and of neurotransmitters, hormones, DNA and RNA synthesis..

Question 13

Water intake , how much it makes up of adults body mass and function?

Answer 13

2-2.8 l a day, 2/3rds of body mass.

Functions: Nutrient transport, temp regulation, biochemical reactions and acts as a medium for reactions.

Question 14

ATP formation and breakdown

Answer 14

Adenine binds with ribose and then with 3 phosphates to form ATP. Bonds between phosphates in ATP can be broken down to release energy for muscle contraction. If another phosphate released ADP forms AMP. Each kilo contains about 5-6 mmol of ATP

Question 15

How much ATP do you use during sprinting

Answer 15

3.7 mmol per kg of muscle of ATP per second- so less than 2 seconds worth of ATP

Question 16

How long can you complete sub-max exercise for?

Answer 16

About 15 seconds- 0.4 mmol ATP kg-1 s-1

Question 17

ATP utilisation equation

Answer 17

ATP+ water — ADP + inorganic phosphate + H+

Question 18

ATP resynthesize

Answer 18

SLP and oxidative phosphorylation

Question 19

Stages of SLP and OP

Answer 19

SLP is production of ATP without oxygen in the cytoplasm and 2 energy systems work- creatine phosphate system and glycolysis- partial glucose breakdown leading to ATP regeneration

OP- needs oxygen and is breakdown of carbs and fats to produce ATP in the mitochondria. Amino acids can be broken down oxidative metabolism but only makes up a small amount of energy production.

Question 20

Stores within the muscle

Answer 20

In the muscle there is a small ATP store. There is also a small phosphocreatine store that can be used by ATP for muscle contraction. Carb stored in muscle is glycogen and is complex branched mixture of glucose molecules. Glucose can be broken off to support OP or SLP. Liver also has a glycogen store and then when broken down provides glucose to the bloodstream and helps fuel the brain.- and can be taken up by the muscle for energy during exercise.

Question 21

What is adipose tissue made up of?

Answer 21

Made of triglycerides and when these are broken down fatty acids can travel to the muscle and be used for energy. There is also fat stored within the muscle that can be used for fat oxidation and energy production within the muscle.

Question 22

Power capacity trade-off

Answer 22

Just need to remember there is a trade off between the max rate and capacity. In intense exercise most energy comes from ATP breakdown and the phosphocreatine system (muscle glycogen breakdown to lactate).- heavy reliance in intense exercise on slp.

Question 23

Describe the power drop off

Answer 23

Power drops off as exercise progresses as muscle cannot produce ATP fast enough to keep producing ATP to the level during the initial sprint. PCR and glycolytic system contributions start high but decrease as PC content decreases within the muscle. Glycolytic system continues to contribute though gives a high acidity which can contribute towards fatigue during high intensity exercise and can increase oxidative phosphorylation’s contribution. OP however cannot produce ATP as fast so power decreases. To keep power higher for longer need to consider nutritional ways to increase pc stores and reduce muscle acidity.

Question 24

In prolongued exercise what is main fuel source?

When is SLP used during prolongued exercise?

Answer 24

Carbs and fats

At the start and during a sprint finish.

Question 25

Energy balance equation

It is a static concept

Answer 25

Energy balance = energy intake - energy expenditure
It is the amount of energy added to or lost from the body after all the physiological systems have done their work for the day.

Question 26

Why would be gain body mass?
Why would we lose body mass?
Why would we have a stable body mass?

Answer 26

Gain body mass if energy intake is greater than energy expenditure for a sustained time period. Once mass increased will not increasing in mass unless energy intake is increase further. Larger mass = larger energy expenditure.
Lose body mass if energy expenditure is greater than energy intake. Stable body mass if energy intake is equal to energy expenditure.

Question 27

Energy intake definition

Answer 27

The metabolizable energy content of food.
4Kcal per gram of carbs
9kcal per gram of fats
7kcal per gram of alcohol
4kcal per gram of protein

Question 28

Energy expenditure definition-

Answer 28

Fuels metabolized to support resting metabolic rate, thermic effect of food and physical activity. Resting metabolic rate makes up 40-70% of energy expenditure.
Thermic effect of food is about 10% of energy expenditure.

Question 29

Physical activity energy expenditure- definition

Answer 29

The energy used in all forms of physical activity- includes NEAT- (non exercise activity)

Question 30

Reason eating loss may not in turn cause weight loss

Answer 30

Sustaining change compensation- Eating less may in turn lead to the athlete exercising less and therefore burning less calories.

Question 31

Challenges when trying to optimise energy balance

Answer 31

It is hard to alter body composition whilst maintaining body mass, maximizing lean tissue during weight gain, maximizing lean tissue during weight loss reduction.
It is also hard to safe but fast weight loss and is hard to maintain energy balance when you have a high energy expenditure

Question 32

Energy balance and availability what do they tell us

Answer 32

Energy balance tells us very little about potential impact on physiological processes.
Energy availability- dietary energy supports physiological processes.

Question 33

Energy availability equation

What is low energy intake?

Answer 33

Energy intake- exercise energy expenditure
Low energy availability is inadequate energy intake in relation to energy expenditure. Energy availability links to energy deficiency in sport syndrome.

Question 34

Problems with low energy intake

Answer 34

Endocrine, gastrointestinal, cardiovascular, physiological, growth and development, neurological , metabolic, immunological , bone health, reproductive function ETC. These problems develop over time and do not just occur in one day

Question 35

What are the energy available thresholds?

Answer 35

Optimal- 45 kcal/kg FFM/d to support non exercise physiological functions.
Clinically low E- 30kcal/ kg FFM/d . Health status may be compromised.
Suggestion- EA of 30-45kcal/kg FFM/d for weight/fat loss. Caveat is the threshold idea debate

Question 36

Energy availability example
Body mass 72 kg, body fat percentage = 8
EI = 4581 kcal/d
EEE= 1600 kcal/d (2 hours cycling)
Calculate energy availability as kcal/kg FFM/d

Answer 36

Lean body mass = 72 x 0.92 = 66.24kg (call it 66)
Energy availability= energy intake- exercise expenditure
4581-1600/66 =45.1667