Effects of training with flow restriction on the exercise pressor reflex

Area of Science:

• Exercise Physiology
• Cardiovascular Regulation
• Sports Science

Background:

• The exercise pressor reflex (EPR) is a crucial cardiovascular response during physical activity.
• Understanding how different training modalities affect the EPR is important for optimizing exercise protocols.

Purpose of the Study:

• To investigate the effect of 5 weeks of endurance training with blood flow restriction (R-training) on the exercise pressor reflex (EPR).
• To compare the impact of R-training versus training with normal blood flow (NR-training) on EPR modulation.

Main Methods:

• 10 participants underwent unilateral knee-extension training for 5 weeks, 4 times/week.
• One leg was trained with blood flow restriction (lower body positive pressure), while the other served as a normal blood flow control.
• EPR was assessed by measuring changes in heart rate (HR) and mean arterial pressure (MAP) during isometric knee extension before and after training.

Main Results:

• R-training resulted in a significant decrease in the EPR, with mean arterial pressure (MAP) increasing by 30 ± 4 mmHg compared to 41 ± 4 mmHg (NR-training) and 38 ± 4 mmHg (control).
• This represents an approximate 25% reduction in MAP response in the R-trained leg.
• Heart rate (HR) responses also showed a similar pattern, with a smaller increase in the R-trained leg (22 ± 4 bpm) compared to NR-trained (28 ± 3 bpm) and control (28 ± 3 bpm) conditions.

Conclusions:

• Peripheral metabolic adaptations induced by relative ischemia during R-training play a significant role in modifying the exercise pressor reflex.
• This suggests that blood flow restriction can be a valuable tool for attenuating the cardiovascular strain associated with exercise.