Exercise intensity prescription in cardiovascular rehabilitation: bridging the gap between best evidence and clinical practice

Abstract

Optimizing endurance exercise intensity prescription is crucial to maximize the clinical benefits and minimize complications for individuals at risk for or with cardiovascular disease (CVD). However, standardization remains incomplete due to variations in clinical guidelines. This review provides a practical and updated guide for health professionals on how to prescribe endurance exercise intensity for cardiovascular rehabilitation (CR) populations, addressing international guidelines, practical applicability across diverse clinical settings and resource availabilities. In the context of CR, cardiopulmonary exercise test (CPET) is considered the gold standard assessment, and prescription based on ventilatory thresholds (VTs) is the preferable methodology. In settings where this approach isn't accessible, which is frequently the case in low-resource environments, approximating VTs involves combining objective assessments-ideally, exercise tests without gas exchange analyses, but at least alternative functional tests like the 6-minute walk test-with subjective methods for adjusting prescriptions, such as Borg's ratings of perceived exertion and the Talk Test. Therefore, enhancing exercise intensity prescription and offering personalized physical activity guidance to patients at risk for or with CVD rely on aligning workouts with individual physiological changes. A tailored prescription promotes a consistent and impactful exercise routine for enhancing health outcomes, considering patient preferences and motivations. Consequently, the selection and implementation of the best possible approach should consider available resources, with an ongoing emphasis on strategies to improve the delivery quality of exercise training in the context of FITT-VP prescription model (frequency, intensity, time, type, volume, and progression).

Keywords: cardiac rehabilitation; cardiovascular disease; cardiovascular health; exercise; exercise test; health; heart disease risk factors; physical activity.

Figure 1

Practical guidance for monitoring exercise intensity using the talk test and the rating of perceived exertion scale. Adapted from: Bok et al. (104) and Festa et al. (113). VT₁, first ventilatory threshold; VT₂, second ventilatory threshold. Talk Test positive: comfortable speech still possible during exercise; Talk Test equivocal stage: characterized by somewhat uncomfortable speech; Talk Test negative: patient unable to read the paragraph comfortably.

Figure 2

Key recommendations for endurance exercise prescription in cardiovascular rehabilitation patients. Adapted from: D'Ascenzi et al. (5), Hansen et al. (6, 7, 21). *Gallardo-Gomez et al. (55). ^†Wood el al. (29). CR, cardiovascular rehabilitation; CVD, cardiovascular diseases; HDL, High-Density Lipoprotein; HF, heart failure; HIIT, high intensity interval training; VTs, ventilatory thresholds.

Figure 3

Exercise test information of clinical case 1. HR, heart rate; HRR, heart rate reserve; HR_rest, rest heart rate; VO₂, oxygen uptake; VT₁, first ventilatory threshold; VT₂, second ventilatory threshold.

Figure 4

Solution of clinical case 1: prescribing moderate endurance exercise intensity using various heart rate-based approaches. CPET, cardiopulmonary exercise test; HR, heart rate; HR_peak, peak heart rate; HRR, heart rate reserve; HR_rest, rest heart rate; MET_peak, peak metabolic equivalent of tasks; VO₂, oxygen uptake; VTs, ventilatory thresholds; VT₁, first ventilatory threshold; VT₂, second ventilatory threshold; %HR_peak, percentage of peak heart rate; %HRR, percentage oof heart rate reserve.

Figure 5

Exercise test information of clinical case 2. HR, heart rate; HRR, heart rate reserve; HR_rest, rest heart rate; VO₂, oxygen uptake; VT₁, first ventilatory threshold; VT₂, second ventilatory threshold.

Figure 6

Solution of clinical case 2: prescribing moderate endurance exercise intensity using various heart rate-based approaches. CPET, cardiopulmonary exercise test; HR, heart rate; HR_peak, peak heart rate; HRR, heart rate reserve; HR_rest, rest heart rate; VO₂, oxygen uptake; VTs, ventilatory thresholds; VT₁, first ventilatory threshold; VT₂, second ventilatory threshold; %HR_peak, percentage of peak heart rate; %HRR, percentage oof heart rate reserve.

Figure 7

Schematic illustration of endurance exercise intensity methods, ranging from minimal to optimal standards, considering high and low resource settings. LVEF, left ventricular ejection; Hb, hemoglobin; HR, heart rate; HR_peak, peak heart rate; HRR, heart rate reserve; HR_rest, rest heart rate; MET_peak, peak metabolic equivalent of tasks; SWT, shuttle walk test; VT₁, first ventilatory threshold; VT₂, second ventilatory threshold; %HR_peak, percentage of peak heart rate; %HRR, percentage oof heart rate reserve; RPE, Ratings of Perceived Exertion; 6MWT, six-minute walk test.