https://orcid.org/0000-0002-6980-0802
Effects from physical activity on cardiovascular risk factors in older adults.
This editorial refers to ‘Effect of 5 years of exercise training on the cardiovascular risk profile of older adults: the Generation 100 randomized trial’, by J. M. Letnes et al., https://doi.org/10.1093/eurheartj/ehab721.
Lethnes and co-workers in this issue of the European Heart Journal report one of the largest randomized controlled studies performed on exercise in older adults.1 Men and women (n = 1567) aged 70–77 from Trondheim, Norway participated in a 5-year study in which they were randomized to two groups of supervised high-intensity (HIIT) or moderately high-intensity training (MICT) twice a week and compared with a control group (Control) that received general advice on physical activity according to national guidelines. The aim was to compare the effects of exercise training in the two training groups together (ExComb), as well as differential effects between the subgroups, HIIT and MICT, compared with the control group on cardiovascular risk factors.
Randomization to 5 years of exercise with regular supervision in older adults failed to show lowered individual and clustered cardiovascular risk factors or a higher VO2 peak for ExComb compared with Control. The authors concluded that 5 years of supervised exercise training in older adults had little effect on cardiovascular risk factors and did not reduce cardiovascular events.
The research question is indeed important, as well as relevant and timely. We need to find new effective methods and to reach the growing numbers of older people. Great interest has been directed towards various forms of high-intensity interval training as an effective way to improve fitness and physical capacity. However, critical voices have also been raised, as it has been suggested that high-intensity exercise would increase the risk of acute cardiovascular events in individuals with, for example, high blood pressure, left ventricular hypertrophy, or silent ischaemia, as well as in elderly and frail individuals.
We live in a pandemic of physical inactivity that has been ongoing for decades. Studies consistently show that both fitness and muscle strength have decreased significantly in all age groups. The COVID pandemic has further aggravated the situation, as severe and long-term illness with immobilization, as well as restrictions of various kinds, have led to further reductions in muscle function and health. Against this background, and in view of the demographic changes that are taking place in the population with more and more older people, it is important to find new effective strategies to increase physical activity.
In 2020 the World Health Organization (WHO) published new guidelines on physical activity and sedentary behaviour. Older adults aged 65 years and older are recommended to limit sedentary time and replace it with physical activity of any intensity. They also recommended at least 150–300 min of moderate-intensity aerobic physical activity per week or at least 75–150 min of vigorous-intensity aerobic physical activity per week. Furthermore, muscle-strengthening activities at moderate or greater intensity that involve all major muscle groups are recommended at least 2 days a week. Varied multicomponent physical activity focusing on functional balance and strength training at moderate or greater intensity is recommended on at least 3 days per week.2
WHO's recommendations thus focus on the whole movement pattern rather than just exercise or training of moderate or high intensity. At a time when elderly people spend 8–10 h per day sitting, moderate to high-intensity exercise 1.5–2 h a week may not be enough to improve cardiovascular risk factors and reduce cardiovascular risk.3 Assuming we are awake ∼115 h a week, 2 h of exercise is probably not enough to affect cardiovascular risk factors if the rest of the time is mainly sedentary. Such an assumption is supported by many cohort studies in which the relationships between sedentary time and future cardiovascular health have been studied. Substantially increased cardiovascular risk remains even after controlling for time spent training or exercising as well as for total physical activity.4–6
It is difficult to perform strict randomized controlled trials in health-conscious people where substantial spill-over effects between groups are likely to occur. This happened in the study by Lethnes and co-authors.1 In addition, we must be humble when we interpret results, and not get caught up in statistical models when striving for statistical significance. Study results need to be wisely interpreted. Notably, in the current study, within-group positive effects were seen on a large number of important cardiovascular risk factors, and even small reductions in the individual risk factors at the population level would provide major health benefits. Furthermore, of note is that no CVD events occurred during supervised training, indicating the safety of HIIT in older adults.
Conflict of interest: none declared.
References
Author notes
The opinions expressed in this article are not necessarily those of the Editors of the European Heart Journal or of the European Society of Cardiology.
