Main outcomes of the HEBE trial: improving cardiorespiratory fitness and body composition through a tailored feasible lifestyle program

Background/Objectives: Lifestyle Modification Programs (LMPs) based on exercise and nutrition aim to prevent/manage chronic diseases and foster well-being. However, moving LMPs from research to medical practice can be challenging, as programs must be both effective and feasible. The primary goal of this study was to assess cardiorespiratory fitness (CRF) changes according to an LMP, measured through VO2max, as a key indicator of health outcomes and intervention efficacy. Methods: In this single-arm intervention study, 100 subjects were enrolled; per-protocol analysis of main parameters was performed on 85 participants (15 were excluded due to medical/technical reasons). A feasible intervention program (of low resource intensity with only two physician/patient encounters) provided personalized exercise prescription, optimized nutritional habits based on the Mediterranean diet and Healthy Eating Plate principles, and supported behaviour change. We assessed CRF through VO2max, a key indicator of health outcomes and intervention efficacy. We also analyzed, using regression analysis, the relationship between VO2max (the gold-standard measure of CRF) and METSpeak, a simpler, feasible parameter of CRF derived from Exercise Stress Testing. Body composition (BC) and AHA diet score were also measured at baseline and post-6-month intervention. Statistical analyses included paired comparisons and multivariable regression to explore factors influencing CRF changes. Results: Analysis on the primary outcome, VO2max, was performed according to the intention-to-treat principle and per-protocol. This feasible protocol resulted in a significant increase in VO2max, improvements in fat-free mass, and a reduction in fat mass. Overall, 42.4% of participants achieved an improvement of ≥1 MET, a change previously associated with reduced mortality risk. Older participants tend to experience smaller improvements in VO2max. Conclusions: Although observing an improvement in CRF and BC following an LMP is not surprising, the strength of the study is to show the feasibility of implementing an effective, feasible LMP into clinical routine, supporting the integration of such programs into clinical practice.