Achieving theorical cardiorespiratory fitness is associated with high-volumen training in a phase II cardiac rehabilitation program
Authors: Lara Vargas J , Palomeque C A , Zamora I K , Avalos J V , Leyva E A , Rodriguez L V , Lastra V J , Juarez M , Camas L , Gomez A E , Morales P J D 
Published: October 2024

Abstract

Background and Puropose
Cardiac Rehabilitation (CR) is an interdisciplinary therapeutic program with demonstrated success rates in reducing cardiovascular outcomes. To obtain these benefits, it is important to achieve a level of cardiorespiratory fitness (CRFIt) that should be close to the ideal according to age and gender (theorical). The best way to measure it, is through VO2p, or with its surrogate value in METs-load. In our Phase II CR program, both aerobic and strength training is supervised 3 times per week, but emphasis is placed on weekly aerobic training volume (TVol) for a sufficient dose, in order to guarantee outcomes. Our hypothesis is that with adequate TVol, CRFit will be achieved at ideal levels (theorical). The aim of the study is to evaluate the safety and achievement in CRFit measured by METs-load in patients with heart disease during a high-volume Phase II CR program.

Methods
Quasi-experimental study of a comprehensive Phase II CR program in which patients were evaluated by initial and final exercise testing. Depending on the result, they were assigned for 4-6 weeks (4 to those patients with &gt;5METs and 6 to those with &lt;5METs) to 3 weekly concurrent training sessions (30 mins of aerobic at 70-85% of their heart rate reserve plus strength training), in addition to the corresponding educational, nutritional and psychological intervention. TVol was calculated by METs/week (METs-minute obtained by ergo or treadmill multiplied by 90 minutes). Progressions were made to achieve a weekly program average TVol&gt;500 METs/week according to guidelines recomendations. An adverse event was defined as malignant ventricular arrhythmias, cardiorespiratory arrest, or death.

Results
A population of 522 patients was analyzed, 72% men, average age of 58.8 years (+-0.59), with coronary ischemic disease, heart failure and cardiomyopathies as the most common heart diseases. Regarding the average theorical METs (8.23, +-0.6), our patients achieved final average METs of 10.2 (+-0.26) and 90.02% (+-0.53) of attendace (Figure 1). The average of TVol were 637.4 (+-37.35) METs/week. The differential between the initial and final METs (Delta1) was correlated by Spearman with the differential between the final METs and its theorical (Delta2) and a significant moderate correlation was found (r=0.32 Spearman, p &lt;0.001). TVol and Delta2 shows a strong and significant correlation (r=0.72 Spearman, p&lt;0.001) (Figure 2). No adverse events were reported in any of the training sessions.

Conclusion
The Phase II CR program with concurrent training only 3 times per week but with TVol&gt;600 METs/week is safe and guarantees a CRFit above the ideal level (theorical). We recommend to measure and fullfill training volume as a strategy to achieve promising results in exercise tolerance and functional capacity in patients with heart disease.