Year: 2024
Type: article
Abstract: This commentary refers to ‘Aerobic, resistance, or combined exercise training and cardiovascular risk profile in overweight or obese adults: the CardioRACE trial’, by DC Lee et al., https://doi.org/10.1093/eurheartj/ehad827 and the discussion piece ‘Aerobic, resistance, or combined exercise training and its outcomes on cardiovascular risk profile in overweight or obese adults via a CardioRACE trial: a gap’, by A. Pontes-Silva and A.L. Lopes, https://doi.org/10.1093/eurheartj/ehae233. We appreciate Drs Pontes-Silva and Lopes for their comment on our paper, Aerobic, resistance, or combined exercise training and cardiovascular risk profile in overweight or obese adults: the CardioRACE trial, which compares the effects of 1 h of time-matched aerobic exercise (AE), resistance exercise (RE), or combined AE and RE (30 min of each AE plus RE), 3 times/week for 1 year, on cardiovascular disease (CVD) risk profile.1 We found that AE and combined exercise, but not RE, improved CVD risk profile. As a possible explanation for these results, Pontes-Silva and Lopes2 state that because continuous AE spends higher energy expenditure than RE with intervals (e.g. resting between sets), the exercise groups should have been matched by energy expenditure, instead of time, implying the cardiovascular benefits of exercise correspond with calories burned or are related to weight loss. However, the overall weight loss in the AE and combined exercise was modest with −1.4 kg and −1.3 kg, respectively, which equated to only 1.5% weight loss over 1 year. Furthermore, determining the energy expenditure of RE is difficult not only due to the interval design of traditional RE prescriptions but also because the muscles continue to burn energy for up to 2 days after RE, called excess post-exercise oxygen consumption,3 which may vary by age, sex, body size, and RE intensity and duration. Therefore, it is challenging for individuals to easily and accurately measure their energy expenditure in RE in the real world, which limits the application of RE. There are also many other interval-based activities such as racket sports (e.g. tennis). In addition, people often use time to set and achieve their exercise goal (e.g. 1 h of running or weightlifting). Thus, the current AE guidelines are based on time (e.g. ≥ 150 min/week of moderate-intensity AE).4 Moreover, most observational studies report RE in minutes (or hours) per week or weekly frequency rather than energy expenditure. Considering these factors, the CardioRACE trial was specifically designed to use time to equalize the dose of exercise between groups for direct public health translation. If energy expenditure was used to match exercise groups, RE would be considerably longer than AE, which may discourage RE since the lack of time is the major barrier to exercise. While there was no improvement in CVD risk profile in RE, we believe that less energy expenditure in RE compared to AE or combined exercise is not the primary explanation. For example, our prior study found that 1–59 min/week of RE had the lowest risks of developing CVD risk factors such as metabolic syndrome and hypercholesterolaemia (except obesity), total CVD events, and all-cause mortality, compared to no (0 min/week) RE (Figure 1).5 We further found that ≥120 min/week of RE showed no risk reductions in all outcomes (except obesity) with plausible explanations of increased arterial stiffness and chronic inflammation. This finding suggests that the RE dose in CardioRACE, which was 180 min/week, was possibly more than enough (or too much) to elicit cardiovascular benefits. However, these data are from observational studies with major limitations such as measurement errors, reverse causation, and confounding. Therefore, randomized controlled trials with multiple doses of RE (e.g. ranging 30–120 min/week) on CVD risk profile are needed. Dose–response associations of resistance exercise with CVD risk factors, total CVD events, and all-cause mortality Although we believe that time-based RE interventions provide more practical real-world implications, we agree with Drs Pontes-Silva and Lopes that this topic highlights the need to establish a universal RE metric, which is important to standardize RE prescriptions across exercise trials and develop useful public health guidelines. D.L. and A.G.B. report grants from the US National Institute of Health (NIH). D.L. and A.G.B. received funding from the National Heart, Lung, and Blood Institute at the US National Institutes of Health (R01HL133069).
Source: European Heart Journal
Authors: Duck-chul Lee, Angelique G Brellenthin
Institution: Iowa State University
Language: English
Subfield: Complementary and alternative medicine
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W4399200883