The Relationships Between Internal and External Measures of Training Load and Intensity in Team Sports: A Meta-Analysis.
Shaun J McLarenTom W MacphersonAaron J CouttsChristopher HurstIain R SpearsMatthew WestonPublished in: Sports medicine (Auckland, N.Z.) (2018)
Measures of internal load derived from perceived exertion and heart rate show consistently positive associations with running- and accelerometer-derived external loads and intensity during team-sport training and competition, but the magnitude and uncertainty of these relationships are measure and training mode dependent.