Fig. 2From: The feasibility of implementing high-intensity interval training in cardiac rehabilitation settings: a retrospective analysisCompliance to the lower intensity intervals of the high-intensity interval training protocol. “Does not comply” refers to a mean HR during classes < 60–70% HRpeak; “Complies” refers to a mean HR during classes with 60–70% HRpeak; “Exceeds” refers to a mean HR > 70% HRpeakBack to article page