Exercise and Ageing

Question 1

2 main body composition decreases with age

Answer 1

• Increased adipose tissue mass

- Decrease lean tissue mass (sarcopenia)

Question 2

Body Composition - Jackson et al (2012)

Answer 2

As age increases:

• Increased body mass until 70/80 then decline
• Increase in adipose tissue (fat)
• Decline in lean mass >50

Question 3

McLeod et al (2016)

Answer 3

• Older individuals tend to be less physically active

- Physically active older individuals have more muscle mass and less adipose tissue compared to inactive old people

Question 4

What is Anabolic Resistance?

Answer 4

• Inability of muscles to grow and respond to training and nutrition

Question 5

Regulation of skeletal mass - Bruce et al (2009)

Answer 5

When we consume protein:

• Increase MPS
• Decreased MPS

3-4 hour post meal

• Decrease MPS
• Increased MPB

Question 6

Protein Undernutrition - Houston et al (2008)

Answer 6

• With age, ability to stimulate MPS is impaired
• Increased muscle mass decline with less protein intake
• Recommended protein intake for older individuals: 0.8g/kg per day

Question 7

Anabolic resistance - Cuthbertson et al (2005)

Answer 7

Ingestion of amino acids:
Old:
- Decreased MPS compared to young when consuming the same amount of amino acids

• MPS doesn’t increased with greater amino acid intake

Question 8

Insulin resistance - Wilkes et al (2009)

Answer 8

Young

• Increase MPB when not fed
• Decreased MPB after feeding

Old:
- No suppression of MPB after feeding due to insulin resistance

Question 9

Anabolic resistance to exercise - Kumar et a (2009)

Answer 9

• Impair muscle protein synthase response to muscle protein contraction with age, which translates into lower muscle mass and strength gains in response to training
• In old people - increase in exercise intensity has little change on MPS

Question 10

Suetta et al (2009)

Answer 10

Gain in muscle mass after periods of disuse (injury/illness) - anabolic resistance may impair recovery

Young:

• Lose 7% of muscle mass with 2 weeks of disuse
• Fully recovered with 4 weeks of training

Old:

• Lose less muscle mass with 2 weeks of disuse
• Does not full recover after 4 weeks of training

Question 11

Weightlifting performance - Maharam et al (1999)

Answer 11

• 2 major US weightlifting competitions

- Linear decline in strength and weightlifting performance with age from >30 yr

Question 12

Leuel and Taylor (1991)

Answer 12

• With age, decrease in number and size of type II fibres

- Maintain type I fibres

Question 13

Stec et al (2017)

Answer 13

• 4 different resistance training programs over 4 weeks for old people
• Increase in muscle mass and strength following 2 high intensity sessions and separates by 1 low intensity sessions per week compared to 2/3 high intensity sessions
• Inflammation much higher after 3 high intensity sessions per week
• Older individuals need more time to recovery due to increase inflammation, therefore low intensity session is important

Question 14

Speed decline - Maharam et al (1999)

Answer 14

• Linear decline in running speed >30 years
• Due to loss of muscle mass and type II fibres
• Older age tends to effect high intensity sports more than low intensity - 400m time significantly more impaired than marathon time

Question 15

Vo2max with age - Pollock et a (2015)

Answer 15

• 0.5% Vo2max decline per year between 55yr-80yr in recreationally active cyclists

Question 16

Vo2max - Colney et al (2000)

Answer 16

• Decrease in Vo2max is partly due to loss in muscle mass - decrease muscle volume and therefore oxidative capacity

Question 17

28 year longditionional study - Colney et al (2000)

Answer 17

Exercisers vs Non-exercisers monitored over 28 years

• Exercisers maintain 2-3 sessions per week
• Exercises still had 0.5% Vo2max decline
• Non-exercises had 2% Vo2max decline
• No exercise accounts for 1.5% of Vo2max decline

Question 18

Cardiac output - Ogawa et al (1992)

Answer 18

• Decrease Sv and Q and therefore Vo2max with age

Question 19

O2 extraction - Coggan et al (1990)

Answer 19

• Increased cpailiarisation in youth elite vs masters athletes
• Increased mitochondria volume in youth elite

However, when comparing masters athletes to fitness equivalent young athletes;

• Muscle capiliarisation and mitochondria had no effect
• Difference was due to increase Q