Fig. 2From: Heart Rate Variability-Derived Thresholds for Exercise Intensity Prescription in Endurance Sports: A Systematic Review of Interrelations and Agreement with Different Ventilatory and Blood Lactate ThresholdsRisk of bias and applicability of included studies as assessed by QUADAS2 [68]. Relative amount of low, high and unclear risk of bias among the included studies for the domains flow and timing, reference standard, index test and patient selectionBack to article page