Nutrition - Energy for Exercise

What is ATP?

The body’s immediate energy currency.

What does ATP stand for?

Adenosine triphosphate.

What happens when ATP breaks down?

Energy is released for muscle work.

What does ATP become after losing one phosphate?

ADP.

What is the ATP breakdown equation?

ATP → ADP + phosphate + energy.

Does the body store much ATP?

No, only enough for a few seconds.

What is metabolism?

All chemical reactions in the body.

What is catabolism?

Breaking molecules down to release energy.

What is anabolism?

Building molecules using energy.

What is TDEE?

Total daily energy expenditure.

What is BMR?

Energy used to keep the body alive at rest.

What is TEF?

Energy used to digest and process food.

What macronutrient gives 4 kcal/g?

Carbohydrate and protein.

What macronutrient gives 9 kcal/g?

Fat.

How much energy does alcohol provide?

7 kcal/g.

What is carbohydrate stored as?

Glycogen.

Where is glycogen stored?

Muscles and liver.

What does muscle glycogen fuel?

The muscle where it is stored.

What does liver glycogen do?

Helps maintain blood glucose.

What is the main fuel for high-intensity exercise?

Carbohydrate.

What is the main fuel for low-intensity exercise?

Fat.

Why is fat useful for endurance?

It provides a large energy store.

Why is fat limited during high intensity exercise?

It produces ATP too slowly.

Is protein a preferred exercise fuel?

No, it mainly supports repair and growth.

When does protein use for energy increase?

Low energy intake, low glycogen, or prolonged exercise.

What are the three energy systems?

ATP-PC, anaerobic glycolytic, and aerobic.

What is the ATP-PC system best for?

Very short explosive efforts.

What fuel does the ATP-PC system use?

ATP and phosphocreatine.

How long does the ATP-PC system dominate?

About 0–6 seconds.

Does the ATP-PC system require oxygen?

No.

What is anaerobic glycolysis?

ATP production from carbohydrate without oxygen.

What duration suits anaerobic glycolysis?

About 30 seconds to 2 minutes.

What does anaerobic glycolysis produce?

ATP, lactate, and hydrogen ions.

Is lactate the main cause of fatigue?

No, hydrogen ions and acidity are more responsible.

What is the aerobic system?

ATP production using oxygen.

What fuels does the aerobic system use?

Carbohydrate, fat, and small amounts of protein.

What exercise suits the aerobic system?

Longer-duration, lower-to-moderate intensity exercise.

What happens to fuel use as intensity increases?

Carbohydrate use increases.

What happens to fuel use as duration increases?

Fat use increases, but carbohydrate remains important.

What is fatigue?

Inability to maintain required intensity or power.

What causes anaerobic fatigue?

PC depletion, acidity, and reduced force production.

What causes aerobic fatigue?

Glycogen depletion, low blood glucose, heat, dehydration, or muscle damage.

What is glycogen depletion?

Low stored carbohydrate in muscle or liver.

Why does glycogen depletion matter?

It reduces ability to sustain exercise intensity.

What helps delay fatigue?

Fitness, pacing, glycogen, hydration, and progressive training.

What do Type I fibres do best?

Endurance and aerobic work.

What are Type I fibres also called?

Slow-twitch fibres.

What do Type II fibres do best?

Speed, power, and high-intensity work.

What are Type II fibres also called?

Fast-twitch fibres.

What is the key fuel for hard training sessions?

Carbohydrate.

What is the key fuel for rest and easy exercise?

Fat.