HMS, BM EQ-Bank 345

Sample Answer

Cardiac output response:

• Increases significantly from resting levels (approximately 5 L/min) to potentially 20-25 L/min
• This increase results from elevated heart rate and stroke volume
• Heart rate can reach 170-190 bpm during high-intensity exercise
• Stroke volume increases initially but may plateau during very high intensities

Ventilation rate relationship:

• Ventilation rate increases alongside cardiac output
• Both respond to the increased oxygen demand of working muscles
• Ventilation rate may increase from 12-15 breaths/min at rest to 40-50 breaths/min
• The increased ventilation supports the greater oxygen uptake and carbon dioxide removal
• This coordination ensures efficient gas exchange at the lungs and tissues

Lactate level relationship:

• During high-intensity training, energy production shifts increasingly toward anaerobic glycolysis
• This leads to increased lactate production and accumulation
• Rising lactate levels stimulate further increases in ventilation rate (respiratory compensation)
• Cardiac output must remain elevated to help transport lactate from working muscles
• Cardiac output also supports oxygen delivery for lactate clearance

Integrative response:

• These three physiological responses work in coordination
• Cardiac output increases ensure adequate oxygen delivery and waste removal
• Elevated ventilation rate supports increased oxygen uptake and carbon dioxide elimination
• Rising lactate levels indicate the intensity exceeds the aerobic system’s capacity
• The body attempts to maintain homeostasis through these coordinated responses

Training implications:

• High-intensity training creates significant stress on these physiological systems
• This stress, when applied appropriately, leads to adaptations including increased cardiac output capacity, improved ventilatory efficiency, and enhanced lactate clearance
• These adaptations collectively improve performance capacity