The relationship between anaerobic threshold and heart rate linearity during cycle ergometry

Area of Science:

• Exercise Physiology
• Sports Science

Background:

• Previous research indicated a heart rate deflection point coinciding with the anaerobic threshold in elite athletes during specific activities.
• This deflection was observed under field conditions.

Purpose of the Study:

• To investigate if the relationship between heart rate, ventilatory response, and anaerobic threshold is present in untrained healthy subjects.
• To determine if heart rate deflection occurs during laboratory-based incremental leg ergometry in this population.

Main Methods:

• Nine untrained healthy adults (22-36 years) underwent incremental leg ergometry.
• Subjects pedaled to exhaustion with increasing power output and pedaling rate.
• Heart rate and expired gases were monitored at 30-second intervals.

Main Results:

• A statistically significant inflection was observed in the ventilatory response to increasing velocity.
• Heart rate response remained linear and did not show a deflection point.
• The previously reported heart rate and ventilatory response relationship was not evident under these laboratory conditions.

Conclusions:

• The anaerobic threshold cannot be reliably determined from heart rate response alone in untrained individuals under laboratory conditions.
• Ventilatory response provides a more accurate indicator of the anaerobic threshold in this setting.
• Caution is advised when interpreting heart rate deflection for anaerobic threshold assessment in untrained populations during laboratory exercise.