19-20 - Adaptations to Altitude & Exercise

Question 1

Define VO2 max

Answer 1

The maximum amount of oxygen DELIVERED to working tissue and UTILISED in aerobic metabolism

i.e. it measures max rate of aerobic metabolism

Question 2

As exercise increases, O2 demand increases and VO2…

Answer 2

Increases

Question 3

What determines VO2 max… outline the 2 main theories…

Answer 3

Utilisation theory (determined by ability to utilise available O2)

Preservation theory (determind by ability of CV system to deliver O2 to active tissues effectively)

Question 4

Typical VO2 max values…

Answer 4

30-40 /kg/min (inactive)

50-60 /kg/min (moderate)

80-90 /kg/min (elite athletes)

(so overall 30-90)

Question 5

VE (minute ventilation) =

Answer 5

VT x fB

Tidal volume * breathing frequency

In other words how much air you breath in a minute

Question 6

VE is typically ___ at rest

Answer 6

VE is typically 6L/min at rest

Question 7

It is the increase in ( max HR / stroke volume) which creates higher cardiac output after training…

Answer 7

It is the increase in STROKE VOLUME which creates higher cardiac output after training…

Question 8

Peripheral adaptations in O2 transport are achieved optimally at VO2 max %?

Answer 8

> 90%

optimisation of peripheral flow

Question 9

Central adaptations in O2 transport occur optimally at 70% VO2 max and take longer to occur…

Answer 9

Weeks to months, rather than weeks

increased stroke volume, cardiac output

Question 10

Delivery of O2 from artery to muscle is less efficient at high altitude due to lower…

Answer 10

Concentration gradient (15mmHg vs 60mmHg)

Question 11

Hypoxia (low PO2) stimulates…

Answer 11

Chemoreceptors to increase rate and depth of ventilation

Question 12

Outline the 2 INITIAL adaptations to altitude…

Answer 12

1 - Increased 2,3 BPG (right shift in curve, more offload)

2 - Increased Renal HCO3 excretion (combat hyperventilation alkalosis)

Question 13

Altitude drop off point for haemoglobin saturation etc.

Answer 13

roughly 2500m

Question 14

Oultine 2 LONG TERM adaptations to altitude…

Answer 14

1. Increased haematocrit
   Intitially: 25% decrease in plasma
   Then: haematopoiesis -> EPO release (21 days)
2. Angiogenesis
   Number of capillaries increases -> increased SA for gas exchange, more respiratory enzymes and mitochondria

Question 15

Staging ascent protocols usually involve 2 phases…

Answer 15

Acclimatisation (2500m) for 7 weeks

Ascent (150m/day)

Question 16

AMS stands for…

Answer 16

Acute mountain sickness

Question 17

Severity of AMS depends on…

Answer 17

Rate of ascent
Altitude
Time spent at altitude
Physical exertion
Invidividual succeptability

Question 18

Symptoms of AMS include…

Answer 18

Headaches, fatigue, dizziness, anorexia, cyanosis

Question 19

AMS may lead to which 2 more severe ailments?

Answer 19

HAPE (High Alt Pulmonary Oedema) and HACE (Hight Alt Cerebral Oedema)

Question 20

HAPE causes…

Answer 20

Damage to capillary walls, leadingn to excess fluid escape and reduces O2 delivery

Question 21

HACE can cause fatal or stroke like symptoms. The onset is gradual (2-3 days) and accompanied by…

Answer 21

Confusion, irritability and nausea

Question 22

HACE is caused by fluid leak from the…

Answer 22

CNS, increase cranial pressure and damaging neurones