Aerobic System
The aerobic system works with oxygen, hours of work at lower intensity. This system breaks down glycogen or fat.
Storage
Only 80 to 100 grams of the ATP is actually stored. This is enough for a few seconds of work. The reason for this is because it is too heavy to store lots. Carbohydrate and Fat storage will determine how the ATP is going to be rebuilt using Anaerobic and Aerobic energy systems.
Carbohydrate
The carbohydrate is stored as Glycogen. The total amount of in well nourished people is between 375 and 475 grams. 375 grams is stored in the muscle. Between 90 and 110 grams is stored in the liver. 5 grams is blood glucose.
- 1 gram of carbohydrate = 4kcal (calories) of energy
- On average 1500 – 2000 kcal stored. This is enough for a 20 mile run.
Fat – Adipose Tissue
Stored lipid is the bodies’ most plentiful source of potential energy. 9 kcal per gram. This is the twice that of carbohydrate or protein. The fat will be approximately 15% of the body mass for males and 25% for females. This means a 70 kilograms male has about 94,500 kcal of energy stored as fat. This contributes to 50% of energy during light to moderate exercise.
Energy balance equation
The triangle on the left represents our food intake, carbohydrates representing the greatest proportion of calories required for the average individual. The other side of the scale represents the three greatest of energy out-put. At the top of the triangle is TEF (thermogenic effect of food). This represents the amount of energy utilized by the ingestion and digestion of all the food we eat which is represented on the left hand side of the scale. A minor amount compared to physical activity and resting metabolic rate, but it does have major significance. The fact you eat food means you will burn calories. In this instance the more time your body spends digesting food the more calories it will burn. In order for a person to gain weight their daily intake of food has to exceed the daily amount of energy used. Weight loss occurs when the daily amount of energy used exceeds the daily amount of food intake. Therefore to lose weight you will have to burn off more calories than you take in like doing more exercise.
Energy in
The factors affecting this are:
- Environmental influences
- Disease state
- Emotional state
- Taste of foods
- Social influences
- Learned preferences
- Metabolic factors
Factors that mostly affect your energy intake are learned preferences. This is because whatever way you have been brought up tends to affect the way you live. It depends on what you ate as a child and the size of the portion you eat. This caused by being set in a certain routine throughout your childhood.
Energy out
- Basal metabolic rate (BMR)
- Physical activity such as intensity, duration, oxygen availability, muscle fibre type used, pre activity nutrition status
- Thermic effect of food
Factors that affect your energy output are how much physical activity you do. This includes how hard you work, how long the activity is done for, how much oxygen that the participant can provide. These factors help you to burn calories.
Diet promoting health
As said by the Guidelines for American – USDA you must:
- “Eat a variety of foods” will help you get everything you need
- “Balance the food you eat with physical activity to maintain or improve your weight”
- “Choose a diet with plenty of grain products, vegetables and fruits”
- “Choose a diet low in fat, saturated fat and cholesterol”
- “Choose a diet moderate in sugars”
- “Choose a diet moderate in salt and sodium”
- “If you drink alcoholic beverages, do so in moderation”
It says you should have 55% of Carbohydrates, 30% of fat and 15% of protein.
Diet promoting Endurance
High carbohydrate, pre-exercise meals improve exercise capacity. CHO (carbohydrate) electrolyte drinks during exercise are of benefit during training and competition. Fluid prolonged exercise helps delay reduction in motor skills. Recovery is improved when 50g of CHO consumed immediately after prolonged exercise and at 1 hour intervals thereafter. While training or competing daily recovery is improved if CHO intake is increased to 10g per kg of body weight each day. Rehydration is quickly achieved if athlete takes fluids equalling 150% of body weight lost during exercise. (key points)(www.gssiweb.com) Pre-exercise meal that is high in carbohydrate 3 to 4 hours before. This is said to improve endurance running and cycling capacity. This is even more effective if a carbohydrate/electrolyte drink is ingested throughout the exercise.
Diet promoting Strength
10 healthy men, three resistance sessions each
At the end of each session they drink 3 different drinks 1 hour after. They would be CHO ( 1g/kg BW), CHO/protein/fat or placebo.
During exercise drink 600-1200ml per hour. Access to fluid during official and non official “time outs”. CHO intake immediately following exercise and at 2 hour intervals until next meal (50g/hr). Total CHO intake should be 9-10g/kg BW over next 24 hours. ( GSSI supplement 70)
- CHO is of utmost importance
- CHO pre exercise
- CHO post exercise
- Hydration is essential ( 1.5x what is lost)
Inadequate nutrition and health
CHD Coronary Heart Disease
- This is linked to obesity
- High cholesterol levels from high saturated fat in the diet
- Cholesterol causes “furring” of the arteries
- This causes a blockage in a coronary artery then part if the heart might die – CHD
- Build up of “plaque”
- Happens in the walls of the arteries which supply the heart with blood
- Restricts the hearts blood supply which will cause pain (angina)
- Stop part of the heart from working (heart attack)
A cause for CHD is smoking. This narrows the arteries. Bad diet and lack of exercises increases your chances of being overweight. Stress, high blood energy and family history raise the chances of CHD.
Obesity
- The fat content of the diet
- Most likely to be an energy balance default
- Too much taken in and not enough lost leads to weight gain
- Medical conditions can be responsible also but environmental conditions are common
- Weight to height ratio greater than 30kg per metre squared
- BMI over 39
A cause of obesity is that industrialised countries which mean not many people have much to do. Lifestyle and employment is also a reason because everyone has a set routine and longer hours and working more days a week. The main reason for obesity is overeating. Convenience foods have something to answer for.
References
American College of Sports Medicine
Guidelines for Americans – USDA
Sport Science Exchange 70
GSSI