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

Hanna M Gardner; Andrew W Scheck; John R Cone; Nathaniel T Berry; Laurie Wideman

doi:10.3389/fspor.2021.692691

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

Front Sports Act Living. 2021 Jul 27:3:692691. doi: 10.3389/fspor.2021.692691. eCollection 2021.

Authors

Hanna M Gardner¹, Andrew W Scheck², John R Cone³, Nathaniel T Berry¹, Laurie Wideman¹

Affiliations

¹ Exercise Endocrinology Laboratory, Department of Kinesiology, School of Health and Human Sciences, University of North Carolina at Greensboro, Greensboro, NC, United States.
² Raleigh, NC, United States.
³ Athletes Research Institute, Chapel Hill, NC, United States.

Abstract

Monitoring session training load to optimize the training stress that drives athlete adaptation and subsequent performance, is fundamental to periodization and programming. Analyzing the internal load experienced by the individual in response to the external load prescribed by coaching staff is crucial to avoid overtraining and optimize training adaptation. Subjective measures provide more information regarding individual training load, as heart rate measures alone do not account for collisions, eccentric muscle actions, muscle soreness, weather conditions, or accumulated training loads, which are paramount to the athlete experience. However, the current subjective metric for interpreting session training load (sRPE) is poorly shaped to the athlete's global response to the whole session, often showing poorer correlations to heart rate (HR) measures during intermittent or high-intensity activity. This study introduces a new metric, the Global Session Metric Score (GSMs), which creates a symmetrical relation between the verbal descriptor and numeric values, as well as more applicable session-specific verbal descriptors for the highest level of exertion. Twenty-four D1 male college soccer field players (age: 20.5 +/- 1.42) wore HR monitors and reported GSMs for all practices and games within an entire season. Linear regression with 10-fold cross validation was used to test the relation between GSMs with B-TRIMP and E-TRIMP, respectively. These models demonstrate good performance with consistency and reliability in the estimation of GSMs to predict both B-TRIMP (R ² = 0.75-0.77) and E-TRIMP (R ² = 0.76-0.78). The findings show promise for the GSMs index as a reliable means for measuring load in both training and matches during a high-intensity intermittent team sport. Future studies should directly compare GSMs to the existing sRPE scale within a controlled laboratory setting and across various other sports. GSMs provides coaches and clinicians a simple and cost-effective alternative to heart rate monitors, as well as a proficient measure of internal training load experienced by the individual.

Keywords: athlete monitoring; fitness periodization; perceived exertion; physiological load; session-RPE; soccer; subjective monitoring.