Exercise physiology Flashcards
Balanced diet
Healthy number of macronutrients (proteins, CHO and fats as well as essential minerals, vitamins and water).
Balanced diet meets energy demands, allows tissue growth and repair, provides energy for metabolic function.
Carbohydrates
55% non-athlete human diet. 70% endurance athlete diet.
Broken down into glucose in bloodstream. Supplies the brain and enables immediate response.
Stored as glycogen in muscles & liver. Limit of 700-800 grams storage (after CHO loaded).
Preferred energy source as it is more efficient.
Used for higher intensity.
Proteins
15% in human diet (athletes and non-athletes). Increased protein for body builders.
Used for growth of structures and repair of body cells.
Only used for energy under extreme circumstances.
Are enzymes they speed up chemical reactions.
Broken down into amino acids.
Fats
25-30% fats non-athlete human diet. 15% athlete diet.
Most plentiful supply (store unlimited amount of fats).
Broken down into free fatty acids to move around in our blood stream.
Stored as triglycerides in adipose (fat) cells.
Rest & submaximal exercise.
Glycaemic index (GI)
Ranking of carbohydrates based on their immediate effect on blood glucose (blood sugar) levels.
Measured on a scale of 1–100.
High GI foods
Break down quickly during digestion.
Immediate effect on increasing blood glucose levels.
Best consumed during and immediately after event.
Triggers an immediate insulin response, so glycogen is pulled out of the bloodstream and stored.
- Pure glucose which has a GI of 100
- Honey
- White bread
- White rice
- Gel shot
- Creamed rice
Low GI foods
Break down slowly during digestion.
Slow release of glucose into blood stream.
Best consumed in pre-event and post event meal to replenish supplies.
Prevents rebound hypoglycaemia.
- Apples
- Lentils
- Kidney beans
- Peanuts
- Navy beans
- Sausages
Rebound Hyperglycemia
Athletes should not consume high GI foods 30 – 120min prior to event.
Rise in blood sugar levels -> hormone insulin being released into blood and lowering sugar levels, glycogen is immediately pulled out of bloodstream and stored in muscles.
Blood sugar levels reduce significantly which impairs CNS functioning during exercise (negative effect on performance.)
CHO loading
Aim: Delay depletion of glycogen store, maximise glycogen stores (extra stored in muscle and liver).
When: 1-day method or 3-day method.
What: 1 day → 8-10g/kg or 3 day → 7-8g/kg in conjunction with exercise taper (decrease volume increase intensity).
Negative: Water retention, increase weight.
Pre event meal
Why: Maximum glycogen stores. Increase glycogen levels leading to glycogen sparing. Ensure gastro–intestinal tract feels comfortable during performance.
When: 3 – 4 hours prior to competition.
What: Low GI, Low protein, Low fats foods (easily digested, slow release of glucose into the bloodstream.)
Fluid: 600-800ml fluid 2hrs prior to event.
Pre event snack
Why: Top up glycogen storage.
When: 30-60mins before event.
What: Low GI snack (easier to digest and avoids rebound hypoglycaemia).
During event meal
Why: Avoid depletion of stored glycogen. Tops up glycogen stores.
When: Events greater than an hour.
What: High GI, 30-60g CHO every hour.
Foods practical and easy to eat (faster release of glucose in the bloodstream, glucose accessed during excersize).
Pre event fluid
Ensure optimal hydration.
1L prior to exercise recommended.
600ml → 3 – 4 hours before the game.
400ml → prior to the game.
During event fluid
200mL every 15mins.
Sports drinks 5-8% CHO.
Post event fluid
For every 1L sweat loss, consume 1.5L water.
Consume slightly salty fluid (osmolality higher, less urination).
