9 | Pre- and post-exercise

Question 1

Purpose of pre-exercise nutrition

Answer 1

Supplement a specific limiting factor in the performance of the exercise. Strengthen the weakest link.

Question 2

Minimum amount of exercise you need per week

Answer 2

50 min/week

Question 3

What are the “weakest links”? How do we strengthen it?

Answer 3

• Glycogen (carb loading)
• Phosphocreatine (creatine)
• Muscle acidosis (buffers)

Question 4

What is carb loading?

Answer 4

Super-compensate glycogen levels. Get glycogen stores up to a level where they haven’t been before.

Question 5

Modern method of carb loading

Answer 5

Day 1. optional depletion exercise
Day 2. regular carb intake, taper exercise
Day 3. ^
Day 4. ^
Day 5. high carb, taper exercise
Day 6. high carb, taper exercise or rest
Day 7. ^
Day 8. complete

Question 6

What’s the point of tapering exercise?

Answer 6

You exercise less, so you burn less carbs than you normally do. Excess carb is stored as glycogen.

Question 7

What’s the difference between modern and old method of carb loading?

Answer 7

Old method recommended low carb intake instead of just maintaining regular. This was found to be not effective / might harm athlete.

Question 8

Glycogen differences between untrained individual, trained, and carb-loaded (mmol/kg of wet muscle)

Answer 8

Untrained: 80
Trained: 125
Carb load: 175-200

Question 9

What’s training low?

Answer 9

Training in carb-deprived state was found to improve performance and glycogen concentration after 10 weeks

Question 10

Why might training low work?

Answer 10

Your body adapts to glycogen-depleted state, so you can withstand it during event. Body becomes better at using fat as fuel.

Question 11

Benefits of protein during workout

Answer 11

• Raise body temperature

- Better blood flow

Question 12

Is carb/protein drink better before or after resistance training? Why?

Answer 12

Before; possibly because the increased blood flow during workout helps circulate nutrients
- no benefit acutely, but may benefit chronically

Question 13

Protein, fat, carb in the pre-game meal (3-4 h before) for elite athlete

Answer 13

• moderate in protein
• low in fat and fibre
• high in carb (140 - 300 g)

Question 14

Pre-game (3 - 4 h before) meal for average exerciser

Answer 14

• 5 - 6 meals per day
• divide calories evenly between those meals
• that’s how much calories you should eat pre-game
• 1/2 those calories should come from carbs (~45 g)

Question 15

Should the average joe exercise before eating?

Answer 15

Sure, he still has enough muscle glycogen, and he won’t harm himself. Since it’s just casual, no need to eat.

Question 16

Should competitive athletes eat before exercise?

Answer 16

Depends on the nature of the activity

• casual training => no
• competition => yes

Question 17

Person should be fuelled with carb before exercise if…

Answer 17

Goal is endurance performance

Question 18

Fuelling with carb may not be necessary if…

Answer 18

• activity is not endurance-based

- goal is conditioning (training low)

Question 19

How long does it take for muscle cells to turnover?

Answer 19

~3 months

Question 20

Muscle protein breakdown vs synthesis: at rest vs after exercise

Answer 20

Although there is less net breakdown after exercise, the overall effect is still breakdown. In order to have muscle synthesis, we need to eat AA + resistance train.

Question 21

When is best time to intake protein in relation to exercise?

Answer 21

• Timing post-exercise did not matter; just do it within 24h window
• Continuously injecting protein not effective; effect on muscle returned to baseline in 2h

Question 22

When is best dose to intake protein in relation to exercise?

Answer 22

• 20 g

- Intermediate approach with 4 x 20 g dose is most effective (take every 3 h

Question 23

Effect of carbs on muscle synthesis

Answer 23

carbs does not enhance muscle protein synthesis when ingested protein is sufficient

Question 24

What is the best method to recover depleted glycogen after exercise?

Answer 24

• Limitation: most studies done in lab on treadmill or cycle
• Early study found feeding immediately after exercise resulted in better muscle glycogen storage (2-3x) vs feeding after 2h
• Later study found that earlier feeding only made a difference at the 2h and 4h measuring window; same result for early and delayed feeding at 8h and 24h

Question 25

Recommendation for replenishing glycogen after exercise

Answer 25

carb intake of 1 - 1.5 g/kg during the first 30 min and again every 2 h for 4 - 6 h to ensure glycogen is replaced

Question 26

How much does the carb time window matter for the average joe?

Answer 26

Not too much; with or without regime, the effects are the same in 24h. At some point, Joe would have to eat, which would naturally replenish his glycogen.

Question 27

How much does the carb time window matter for an athlete?

Answer 27

Depends on nature of activity

• Competition => yes
• Training => maybe not, training low

Question 28

Does adding protein to the carb help with replenishing glycogen?

Answer 28

No, protein itself does not make a difference when it comes to glycogen. However, the extra calories may help, and there are additional benefits of protein.