Factors limiting exercise Flashcards
Effect of altitude on performance? (PO2)
lower PO2 results in poorer aerobic performance
Effect of altitude on VO2 max?
decreased VO2 max (3% for each 1000ft elevation)
At what elevation do you start losing cardiac output due to a fall in max HR?
elevations higher than 12,000ft
How does altitude effect RPE?
RPE is greater due to working at higher percentage of VO2 reserve
Effect of altitude on submaximal exercise?
- higher heart rate due to lower oxygen content (heart needs to beat faster)
- requires higher ventilation due to reduction in number of oxygen molecules per liter of air
What is the Hypoxia ventilatory response (HVR)?
increased ventilation to maintain arterial oxygen content
What kind of hypoxia ventilatory response do fit athletes have at sea level?
blunted HVR => poor performance at altitude
What is the most important adaptation that occurs with exposure to high altitude?
production of more RBCs and an increased blood viscosity
What do climbers do to be successful in high altitudes?
hyperventilation - decreases acidity and increases oxygen binding to hemoglobin
Effect of training at altitude on VO2max for trained individuals?
1-8% increase, due to degree of saturation of hemoglobin
Advantages of living high and training low?
increase hemoglobin by living at high altitudes and being able to increase training intensity by training at low altitudes
Altitude related illness is due to what?
due to a lack of partial pressure of oxygen in the blood stream
3 types of altitude related illness?
- Acute Mountain Sickness (AMS)
- High-Altitude Pulmonary Edema (HAPE)
- High-Altitude Cerebral Edema (HACE)
Neurological changes associated with increased altitude?
- loss of consciousness
- hallucinations
- learning and special memory impaired
- dizziness and tingling
Health risk to exercising in hot/humid environments?
Inability to lose heat to maintain homeostasis
- impaired performance
- hyperthermia
Cardiovascular response to exercising in heat?
- active muscles and skin compete for blood supply
- SV decreases
- HR gradually increases to compensate for lower SV
What metabolic cycle maintains lactate levels in the blood?
Cori Cycle
Metabolic response to exercise in the heat?
the body is unable to remove lacate efficiently so lactate levels increase in the blood
High volumes of sweat cause what effects to the body?
- blood volume decreases
- loss of minerals and electrolytes
- lack of urination due to a loss of water reabsorption
5 heat related problems?
- hyperthermia
- heat cramps - due to high levels of lactate and loss of electrolytes
- heat exhaustion
- heat stroke
- heat syncope
6 symptoms of acclimatization to the heat?
- decreased HR, core and skin temperature at rest and submax exercise
- increased plasma volume at rest
- earlier onset of sweating
- higher sweat rate and capacity
- reduced sodium chloride loss in sweat
- reduced skin blood flow
How to achieve acclimatization to heat?
exercise in the heat for an hour a day for 10-14 days at less than 50% of your VO2 reserve or 30-35 min a day at 75% of VO2 max
How does your heart rate respond to cold?
increase
What occurs cardiovascularly at 93.2 degrees F
initial tachycardia progresses to brachycardia
What occurs cardiovascularly at 86 degrees?
atrial fibrillation and brachycardia
what occurs cardiovascularly at 66 degrees?
asystole - heart stops
Respiratory response to cold temp?
- initially increases but then depresses at 87.8 degrees F
- increase mucous production
- impaired oxygen delivery to the tissues
Long-term cold acclimatization involves what three things?
1) increased basal metabolic rate
2) decreased peripheral circulation
3) increased body fat
