Adaptations to exercise Flashcards
What are the post-training adaptations in plasma and RBC volume?
1) ↑ blood volume
2) ↑ absolute RBC volume
3) ↓ blood viscosity
4) ↓ hematocrit
How are RBC and plasma volume changes after exercise?
1) Hypoxia → ↑EPO from kidney → ↑RBC prod.
2) Exercise stimulates albumin synthesis → ↑ albumin → ↑ oncotic pressure → ↑ plasma volume
What type of left ventricular hypertrophy is present in endurance athletes?
Eccentric
How does the LVH seen in endurance athletes differ from that of hypertensive px?
Hypertensive heart have:
↓ LVDD
↓ Distensibility
What is the main reasons for ↑ max cardiac output in endurance athletes?
↑ LV diameter, ↑ LV wall thickness, ↑ LV mass
What are the structural changes of the heart seen in endurance athletes?
↑ LV diameter, ↑ LV wall thickness, ↑ LV mass
Why is sinus bradycardia seen in endurance athletes?
LVH → ↑SV
→ ↓Vagal tone → ↓PNS
→ ↓SA firing rate → ↑ PR interval → 1° AV block
overall ↑ length of cardiac cycle → sinus bradycardia
Why is there elongated PR intervals in ECGs of endurance athletes?
LVH → ↑SV → ↓SA firing rate → ↑ PR interval → 1° AV block
After endurance training,
SVmax (↑/↓), SVrest (↑/↓)
HRmax (↑/↓), HRrest (↑/↓)
SVmax ↑, SVrest ↑
HRmax same, HRrest ↓
Why does HR max not increase with endurance training?
↑HR beyond a certain point → ↓time for ventricular filling → ↓CO
Why is there shortened QT intervals/early repolarisation in ECGs of endurance athletes?
Shift in T wave → ↑ time for ventricular filling
Why would there by RBC in urine from a px who is an endurance athlete?
Dehydration → bladder wall chaffing
Why would AST/ALT be elevated in an endurance athlete?
Biproducts of muscle damage
What are the ECG changes in an endurance athelete?
1) ↑RR interval (sinus bradycardia)
2) ↑PR interval (↓SA firing rate)
3) ↓QT interval (early T wave)
