Lecture 4 - Continuous vs Interval Training

Question 1

List the 12 muscular adaptations of aerobic training?

• Cellular
• Anatomical

Answer 1

Cellular

• Increased mitochondrial content and size.
• Increased glycogen concentration
• Increased oxidative enzyme activity
• Increased myoglobin concentrations
• Increased glycotic enzyme activity
• Increased uptake of blood fats
• Increased fat utilisation
• Decreased glycogen utilisation
• Decreased lactate production.

Anatomical

• Increased capillaries per fibre
• Decreased diffusion distance of 02 substrates and metabolites between blood and muscle
• Fast twitch fibres become slower

Question 2

Why is iron important for athletes and how much 02 binds to it.

Answer 2

Iron is important because it has a high affinity for 02 binding and transport, so depleted can hinder performance.

Each haemoglobin molecule has 4 iron groups, meaning 1 haemoglobin can carry 4 O2 molecule.

1g of haemoglobin can carry 1.34ml O2

Question 3

What are the effects of endurance training on muscle metabolic homeostasis during exercises.

Answer 3

Homeostasis in maintained more effectively because their is less PCr and glycogen utilisation and a reduced building of of acidosis because of the better buffering capacity.

Question 4

What is the best training method for well trained athletes ?

Answer 4

SIT as it can improve performance even in well trained athletes. However you cannot entirely remove the MICT as it is essential to baseline conditioning and central adaptions.

Question 5

What are the central cardiovascular adaptations to exercises training ?

Answer 5

Reduced HR
Increased QMax
Increased blood volume (plasma, RBC, Heamaglobin)

Question 6

How does endurance training improve endurance performance. An overview.

Answer 6

When running at the same velocity as before training an individual is:
– More economical so uses less energy
– Depletes the energy reserves less (improved economy and fat oxidation spares muscle PCr and glycogen)
– Produces less metabolites linked to muscle fatigue (ADP, Pi, H+)
– Able to perform better in the sprint finish
• Capable of running faster for the same depletion of energy reserves and metabolite accumulation as before training
– We can run the ‘kick’ out of our competitors.

Question 7

What are the implication of having an increased heamatocrit (ratio of RBC to toal volume).

Answer 7

Increased blood volume and 02 carrying capacity.

Question 8

How much energy in ATP do you gain from glycogen vs fats ?

Answer 8

Glycogen = 39ATP
Fat = 129ATP

Question 9

What is the problem of work matching performance?

Answer 9

It can skew the conclusion as you may perform a few sprints, however, if you only completed 30 mins moderate activity it is not enough to stimulate a response.

Question 10

What are some standard adaptations to endurance endurance training ?

Answer 10

• VO2max
• Lactate threshold
• Economy

Question 11

Describe the 4 signalling cascades for endurance adaptation from training?

Answer 11

• Low glycogen leads to the activation of MAPKp38 + AMPK.

High levels of ADP,AMP AND low PCr lead to activation of AMPK

When calcium is released this stimulates caMKII.

Adrenalin stimulates activation of PKA.

These four action then lead to the activation of PGC1a, which leads to mitochondrial biogenisis, fibre type conversion and blood vessel creation.

Question 12

In 4 weeks time is it possible to increase mitochondria ?

Answer 12

No

Question 13

What is the most effective method of training to improve VO2max?

HIIT, MICT or SIT ?

Answer 13

HIIT is best as it has the biggest response for developing SV, Qmax and VO2.

Question 14

What is the best method to improved mitochondrial respiration

HIIT, MICT or SIT ?

Answer 14

SIT is best because it caused the largest disturbance, therefore allowing greatest remodelling adaptation, however, this only increased the effectiveness of the mitochondria not the overall content.

Showed highest levels of PGC1a and P53 increases.

Question 15

What is a typical sprint interval training session?

Answer 15

30 seconds interval with 4 min recovery
4-7 repetitions
90-95% HRmax
170% Peak aerobic power

Question 16

How does blood volume increase?

Answer 16

Initial because of an increase in plasma volume

However, with an extended period it is via increases in red blood cell count.

Question 17

For sprint interval training answer the following:

• What systems does it improve?
• What structural effects does it have ?
• Does this translate into performance improvements in races?
• Should it be the training of choice ?
• What athletes should use this
• What is another effect of SIT that needs to be considered.

Answer 17

• SIT can improve aerobic and anaerobic metabolism
• SIT can increase skeletal muscle hypertrophy, % of IIa fibres and capillarisation
• SIT can improve sprint, repeated sprint and endurance performance (at least up to around 10 km)
• SIT should be the ‘endurance training’ of choice for athletes wishing to also improve strength performance
• SIT should be used by team sports athletes due to its numerous metabolic and performance improvements
• Continuous training more important for longer distance athletes.
• SIT can increase skeletal muscle hypertrophy, Meaning that if weight is an important factor this may need to be limited of applied intelligently.

Question 18

What does HIIT do to onset of fatigue ?

Answer 18

Central fatigue is reduced allowing greater peripheral fatigue as muscles are not limited so can contract for longer and harder.

Question 19

What is a typical high intensity training session?

Answer 19

1-5 mins exercise with similar recovery.
6-20 repetitions
85-90% HRmax
75-100% VO2max

Question 20

Give an overview of the effects of endurance training on the following:

• Central and peripheral cardiovascular adaptations.
• Energy utilisation
• Substrate usage within cells
• Metabolite accumulation (Which types change
• Feedback responses.

Answer 20

Post endurance training
– ↑ Qmax, SV, muscle blood flow, capillarity density, mitochondrial content AND efficiency
– ↑ Fat oxidation, ↓ CHO oxidation
– ↓ Muscle glycogen and PCr decline
– ↓ Muscle ADP, Pi, H+, K+ and lactate accumulation
– ↓ Muscle afferent feedback
– ↓ Central fatigue
– ↑ Pain tolerance
– Allows the development of greater peripheral fatigue
– Improved performance

Question 21

How are muscle ion transporters effected by exercise training ?

Answer 21

The monocarboxylate (MCT) and exchanger isoform 1 (NHE) which are responsible for removing lactate and H+ from the muscle ino the blood were enhanced.

Moreover the Na, K pump was enhanced also, meaning that any potassium accumulating outside of the muscle is pumped back in, ensuring that there is no interference in muscle excitability, which potassium can cause fatigue.

Question 22

What is needed to increase mitochondrial content best ?

Answer 22

Mitochondrial content responds best to a increase in volume of training at a moderate/ low intensities, as apposed to increases in intensity.

Question 23

How does a 30 second wingate correlate to the work done during normal cycling ?

Answer 23

Equates to 5 mins moderate cycling.

Question 24

What causes the increase in red blood cell count ?

Answer 24

When the blood become oxygenated during exercise performing this repeatedly cause the kidneys to secrete the erythrocyte stimulating hormone erythropoietin (EPO).

EPO stimulates RBC production in bone marrow of long bones which increases the count of RBC and haemoglobin in blood.

Question 25

Why does HR reduce with endurance training ?

Answer 25

Improvement of Stoke volume via left ventricular hypertrophy and the increased blood volume.

This allows the chamber to fill to greater degree improving the ejection fraction, and subsequent stoke volume per beat, thus improving overall Qmax.

Therefore, the heart does not have to beat as often to supply the same amount of blood.

Question 26

How does endurance training change fibre recruitment ?

Answer 26

Less recruitment of type II muscle fibres at the same exercise intensity after training

• Beneficial since type II muscle fibres are less economical (require more energy) and become fatigued quicker.

Question 27

What are the benefits of greater fat oxidation ?

Answer 27

• More ATP produced than carbohydrate
• Huge fat reserves compared to carbohydrate
• Increasing fat oxidation spared the limited muscle glycogen reserves.

Question 28

Summarise the central adaptions to endurance training ?

Answer 28

• Can pump more blood per beat.
• Muscle blood flow is increased.
• Blood contains more O2
• Muscle 02 delivery is increased.

Question 29

What is Ficks equation for oxidative metabolism and how is is broken down?

Answer 29

VO2 = CO x a-vO2 difference.

The CO and the (a) represent the Central O2 delivery (Hence the CO)

Whereas the vO2 difference represents the O2 uptake by the muscle..

Question 30

What are the factors that determine mean race pace ?

Answer 30

Lactate threshold and critical velocity = sustainable %VO2max

VO2max and sustainable %VO2max = performance VO2

This represents the highest sustainable rate of ATP resynthesis

running economy fit in here to determine how much energy is demanded at a certain speed and this gives mean race pace.

Question 31

Name the SPORT AND FITT acronyms.

Answer 31

Specificity
Progression
Overload
Reversibility
Tedium

Frequency
Intensity
Type
Time

Question 32

What happens to energy utilisation after endurance training?

Answer 32

Fat oxidation increases and carbohydrate oxidation decreases.

Question 33

What is a Typical example of a moderate intensity continuous training session ?

Answer 33

60 minutes
70% HRmax
50-80% VO2max / Peak aerobic power.

Question 34

What is sprint interval training good for ?

Answer 34

SIT is very effective at getting peripheral improvements because of its large changes in the energy charge of the cells. It is also very time efficient.

Question 35

What is the other advantage of having a greater fat oxidation for energy systems ?

Answer 35

Means you will not rely on anaerobic energy as heavily, meaning less depletion of crucial PCr and glycogen stores, and lower accumulation of Pi, ADP and H+ in the muscle

Question 36

How do the HITT and MICT training methods effect pain sensation ?

Answer 36

HIIT improved pain sensation.