Exercise

Question 1

How are carbs found in the body? What’s the use of carbs in exercise?

Answer 1

Liver glycogen, muscle glycogen and glucose in body fluids
The contribution of carbohydrate to energy demands increases with the intensity of exercise. •A high carbohydrate diet (70% diet) and carbohydrate feeding (~1 g/min) can improve endurance exercise performance lasting >60 min.

Question 2

How is fat found in the body?

Answer 2

Subcutaneously and intramuscularly

Question 3

What’s an issue with fat oxidation?

Answer 3

The energy for sub-maximal exercise is provided by the oxidation of carbohydrate and fat.
It takes a lot more time to deplete than carbohydrates.

Question 4

What’s the link with dietary carbohydrate and endurance performance?

Answer 4

Higher glycogen stores provide energy for higher excerise endurance time

Question 5

What transporters are involved in glucose and fructose transfer?

Answer 5

SGLT1 to GLUT2 glucose transnfer

GLUT5 to GLUT2 Fructose

Question 6

How is the oxidation of combined ingestion of glucose and fructose during exercise different?

Answer 6

Total exogenous carbohydrate rates were 54% higher with
combined glucose and fructose ingestion
Jentjens et al. J Appl Physiol 2004

Question 7

Name the carb amount and type recommendations for athletes working:
1-2 hours,
2-3 hours and
more than 2.5 hours.

Answer 7

1-2 hours 30g/hour single carbs,

2-3 hours 60g/hours or multiple transportable carbohydrates

> 2.5 90g/hr only multiple transportable carb

Question 8

How does one change the proportion of muscle protein?

Answer 8

Changes in muscle protein result from a balance between protein synthesis and breakdown
Must have
↑ Muscle Protein Synthesis (MPS)
and/or
↓ Muscle Protein Breakdown (MPB)

Question 9

How much exercise is needed to build muscle?

Answer 9

A dose response exists
↑ Intensity = ↑ Anabolic cellular signalling

20% one repetition maximum (1-RM) the lowest intensity to observe a measurable MPS response.
Guidelines:   
	- 8-12 repetitions 
           - 70-80% 1-RM
	- 3 days per week

Question 10

How long does exercise stimulate MPS for? What’s the maximal effective dose of protein for stimulating post-exercise MPS?

Answer 10

Exercise stimulates MPS for up to 24h

The maximal effective dose of protein for stimulating post-exercise MPS rates is 20 g

Question 11

How does age affect the body’s MPS reponse to exercise?

Answer 11

20-30 year male: ~50% of body weight is muscle mass
75-80 year male: ~25% of body weight is muscle mass

FSR = fractional synthetic rate

FSR response to exercise ~30% lower in older subjects
Elderly have ‘anabolic resistance’ to dietary protein
Protein supplementation does not further increase muscle mass after resistance training in the elderly