altitude and performance

Question 1

Moderate altitude vs. high altitude vs. extreme altitude

Answer 1

moderate: 1500m - 3000m
high: greater than 3000m
extreme: over 5500m

Question 2

Describe the physics of barometric pressure

Answer 2

barometric (air) pressure decreases as altitude increase

Question 3

Oxyhemoglobin dissociation curve

Answer 3

only a small change in percent saturation of hemoglobin is observed with decreasing PO2 until an altitude of about 3000m
- measurable negative effects on VO2 max have been noted at altitudes as low as 1200m

Question 4

How is the physical environment changed at altitude

Answer 4

• air temperature decreases by 6.5C per 1000m of altitude
• air becomes increasingly dry –> water loss via respiratory tract is higher
• UV radiation is more intense –> sunburns

Question 5

What mountain is known as the savage mountain

Answer 5

K2

Question 6

Effects of altitude hypoxia on cardiovascular system

Answer 6

• over first week at altitude, cardiac output falls to or below sea level values for same VO2 and there is a more progressive increase in O2 extraction –> more efficient method to delivering more O2
• hemoglobin concentration starts to increase during the first 2 days at altitude due to a decrease in plasma volume and increase in RBC production by red bone marrow
• shift O2 dissociation curve to right

Question 7

Effects of hypoxia on pulmonary system

Answer 7

decreased alveolar PO2 –> decreased arterial PO2 –> stimulation of aortic and carotid chemoreceptors –> increase ventilation –> increase PA02 and PaO2

Question 8

Higher altitudes have favourable effect on

Answer 8

jumping, sprinting and throwing events

Question 9

Why is VO2 max approx decreased by 30% above 14000ft

Answer 9

1. decreased oxygen content in arterial blood –> decrease a-VO2 difference in maximal exercise
2. decreased in cardiac output due to decrease in maximum heart rate and stroke volume

Question 10

Starling mechanism

Answer 10

Decrease in maximal stroke volume is most likely due to reduction in venous return which is caused by the decrease in blood volume

Question 11

The number of days needed to acclimatize depends on the altitudes
9000ft –>
12000ft –>
15000ft –>

Answer 11

9000ft –> 7 - 10 days
12000ft –> 15 - 21 days
15000ft –> 21 - 25 days

Question 12

Give 2 reasons why muscle and blood lactate levels are higher at altitude during heavy exercise

Answer 12

1. Since the VO2 max is reduced, any given workout requires a higher percentage of VO2 max to perform
2. there is a reduced blood buffering capacity due to some amount of excretion of bicarbonate via kidneys

Question 13

It has been observed that acclimatization stops and physical condition and mental function begin to deteriorate at 17000ft

Question 14

What happens after high altitude exposure for long than 2 weeks

Answer 14

reduction is body fat and lean body mass due to appetite depression

Question 15

How long should endurance athletes acclimatize before their major competition

Answer 15

for endurance athletes 3-4 weeks
for non-endurance athletes they can close to the time of competition

Question 16

what is “sleep high, train low”

Answer 16

living at altitudes, but then going down to lower altitudes for a few a hours per day to train

Question 17

Performance after return to sea level

Answer 17

There is no significant evidence to prove training at altitude improves sea level performance

• no VO2 max increase

Question 18

Adaptions to altitude which should increase VO2 max on return to sea level

Answer 18

1. increase in hemoglobin concentration
2. local muscle adaption (increases in # of mitochondria)

Question 19

Adaptations which hinder performance to return to sea level

Answer 19

1. decrease in maximal heart rate and stroke volume which persists for a few weeks after
2. decrease in blood buffering capacity for lactic acid
3. increased VE for a given workload –> extra oxygen going to your respiratory muscles

Question 20

The purpose and benefit to the “live high train low”

Answer 20

It gives the beneficial physiological altitude adaptations, while maintaining sea level performance

this gives better sea level performance then living and training at altitude then returning to sea level

Question 21

Prevention in altitude illness

Answer 21

1. staged ascent - slow ascent to altitude while climbing (don’t go higher till symptoms decrease)
2. avoid alcohol or depressant drugs
3. High carbohydrate diet (at least 70% carbs)
4. appropriate exercise level
5. drug prophylaxis (diamox)
6. fluid ingestion (dink enough to produce little urine)
7. different people acclimatize at different lates (it is not related to fitness)

Question 22

Acute mountain sickness

Answer 22

• The most common altitude illness
• occurs 12 - 36 after arriving at altitude and last 2 - 3 days
• dependent on elevation, rate of ascent and individual susceptibility

symptoms - vomiting, nausea, dizziness, headache

treatment - acclimatization or descent

Question 23

High altitude pulmonary edema (HAPE)

Answer 23

pulmonary edema - accumulation of fluid in alveoli
decreased diffusion capacity for oxygen

• occurs about 3000m and takes 36-72 hrs to become obvious
• individuals can be any age, but mostly for people who ascend rapidly
• altitude above sea level, rate of ascent to altitude, individual susceptibility

symptoms: shortness of breath, severe fatigue, insomnia

treatment: descend to lower altitude
- diuretics, diamox

Question 24

why is maximal exercise performance reduced at altitude? how would you expect an individuals performances in sprint events, endurance events, and throwing events to change at altitude?

Answer 24

hypoxia limits O2 availability = lover VO2 max, less o2 to heart. In shorter duration activities, effect is less because activities dont depend as much on aerobic metabolism. throwing and jumping events favored (?) at altitude as force of gravity is less.

Question 25

High altitude cerebral edema

Answer 25

-accumulation of excess fluid in the brain -rare below 3600m symptoms: headache, loss of coordination, hallucinations, confusion treatment: descend, diuretics, diamox and dexamethasone

Question 26

Treatment of altitude illness is based on four principles

Answer 26

1. stop ascent in presence of symptoms 2. descend if no improvement of if condition worsens 3. descend immediately if HACE, loos of coordination or change in consciousness are present 4. ill person should never be left behind alone or be sent down alone

Question 27

What is the effect of hypoxia?

Answer 27

Hypoxia in the systemic arterioles is vasodilation and hypoxia in the lungs causes vasoconstriction