The Global Session Metric Score (GSMs): A Modified Session-Specific Exertional Index

Area of Science:

• Sports Science
• Exercise Physiology
• Athlete Monitoring

Background:

• Optimizing training load is crucial for athlete adaptation and performance.
• Current subjective training load metrics like session-Rating of Perceived Exertion (sRPE) have limitations in capturing the athlete's global response.
• Heart rate measures alone do not account for all factors influencing internal training load.

Purpose of the Study:

• Introduce and validate a new metric, the Global Session Metric Score (GSMs), for assessing internal training load.
• Evaluate the relationship between GSMs and established training load metrics (B-TRIMP and E-TRIMP).
• Provide coaches and clinicians with a simple, cost-effective, and proficient alternative for monitoring training load.

Main Methods:

• Twenty-four NCAA Division 1 male soccer players participated throughout an entire season.
• Players wore heart rate monitors and reported GSMs for all training sessions and games.
• Linear regression with 10-fold cross-validation was used to assess the correlation between GSMs and B-TRIMP/E-TRIMP.

Main Results:

• The Global Session Metric Score (GSMs) demonstrated good performance in predicting both B-TRIMP (R² = 0.75-0.77) and E-TRIMP (R² = 0.76-0.78).
• GSMs showed consistency and reliability in estimating training load.
• The metric establishes a symmetrical relation between verbal descriptors and numerical values for exertion.

Conclusions:

• The Global Session Metric Score (GSMs) shows promise as a reliable method for measuring internal training load in high-intensity intermittent team sports.
• GSMs offers a simple, cost-effective alternative to heart rate monitors for assessing training load.
• Further research should compare GSMs directly with sRPE in controlled settings and across different sports.