A comparison of traditional and modified Summated-Heart-Rate-Zones models to measure internal training load in basketball players

The Summated-Heart-Rate-Zones training load (SHRZ TL) model is used to measure internal loading; however, a major limitation of this approach is the use of broad heart rate (HR) zones to quantify exercise intensity. Therefore, this study aimed to compare SHRZ TL outcomes derived using the traditional model and modified approaches using smaller HR zones. HR responses were monitored in 15 semi-professional basketball players during preparatory training to calculate SHRZ TL using the traditional approach with 10%HRmax zones (SHRZ10) and modified approaches with 5%HRmax zones (SHRZ5) and 2.5%HRmax zones (SHRZ2.5). Significant (P < 0.001) differences were evident in SHRZ TL between SHRZ10 (254.2 ± 41.7 AU) and SHRZ5 (275.9 ± 43.3 AU, unclear, small) as well as SHRZ2.5 (286.7 ± 44.3 AU, very likely, moderate). Use of SHRZ2.5 provides novel insight regarding internal loading in basketball players and may carry greater sensitivity for detection of maladaptive and adaptive responses to training.