Ideal Combinations of Acceleration-Based Intensity Metrics and Sensor Positions to Monitor Exercise Intensity under...

Area of Science:

• Sports Science
• Biomechanics
• Exercise Physiology

Background:

• Objective monitoring of exercise intensity is crucial for training prescription and performance analysis.
• Acceleration-based intensity metrics (AIMs) offer a promising alternative to heart rate monitoring, especially in dynamic sports.
• Understanding optimal sensor placement for AIMs is key to accurate intensity assessment.

Purpose of the Study:

• To quantify the relationship between percentage of heart rate reserve (%HRR) and two AIMs (Player Load per minute [PL/min] and mean amplitude deviation [MAD]).
• To evaluate the influence of sensor position (shank, trunk, wrist) on the accuracy of AIMs across different sports and intensities.
• To identify optimal sensor placement for monitoring external training load.

Main Methods:

• Fourteen participants performed running, basketball, and badminton at varying intensities.
• Heart rate was monitored using a chest strap, while accelerometers were placed on the left wrist, trunk, and right shank.
• PL/min and MAD were calculated and correlated with %HRR for each sensor position and sport.

Main Results:

• The shank sensor position demonstrated the strongest correlations with %HRR across all three sports for both AIMs.
• In running, shank and wrist (PL/min) showed strong correlations (r=0.777-0.778).
• Basketball and badminton showed consistently stronger correlations with AIMs on the shank compared to the wrist or trunk.

Conclusions:

• The shank is the ideal sensor placement for both PL/min and MAD to accurately monitor external exercise intensity in running, basketball, and badminton.
• Wrist placement, particularly using PL-derived metrics, represents a viable secondary option for intensity monitoring.
• These findings provide valuable insights for optimizing wearable sensor use in sports performance and training.