An analysis of the results from several clinical trials studying the benefits of exercise on cardiovascular health suggests that these benefits are not the same for everyone.

The review, which appears in the Journal of the American Heart Association, also suggests—per a release from Brown University—that there are nuances that could be important to physicians and their patients as they consider whether to begin an exercise program.

According to the release, researchers from Brown University analyzed the results of 160 randomized clinical trials of the cardiometabolic benefits of exercise, involving nearly 7,500 participants to gain a better understanding of how exercise improves health and whom it helps the most.

Lead author Xiaochen Lin, a doctoral student in the Brown University School of Public Health, says in the release that, “because the exact mechanisms linking exercise to intermediate health outcomes are not clear, we also wanted to examine the effects of exercise on intermediate biomarkers that may potentially mediate the cardioprotective effects of exercise.”

Corresponding author Dr Simin Liu, a Brown professor of epidemiology and medicine, notes in the release that, based on the study’s findings, exercise is not universally effective for different intermediate outcomes and subgroups of participants.

“Even though exercise may benefit most people under most circumstances, it does not mean that the same exercise program or therapy should be prescribed to everyone,” Liu states in the release.

For example, the release explains, the researchers found that for some of the measures the studies tracked, men often benefitted more than women, people under 50 benefitted more than people over that age, and people with either type 2 diabetes, hypertension, or hyperlipidemia benefitted more than people with none of those conditions.

This finding includes the review’s main clinical indicators of cardiorespiratory fitness (CRF), which measures how well the heart and lungs deliver oxygen to the muscles during physical activity, the release explains. CRF is a strong predictor of cardiovascular disease (CVD), according to Liu in the release.

According to their findings, the researchers note, exercise appears to affect total cholesterol in that it may help lower “bad” LDL cholesterol for at least some people and raise “good” HDL for most. However, in their study they write, the release says, “the proportion of CVD risk that could have been reduced by exercise via effects on total cholesterol and LDL cholesterol is much lower than what has been observed previously.”

Instead, the researchers note, per the release, some of the significant benefits of exercise appear to lie in reducing insulin resistance and inflammation based on how those biomarkers performed in the studies.

Liu says in the release that while the review confirms the wide-ranging benefits of exercise, it is still just one of the areas that doctors and patients should consider manipulating.

“Besides exercise, there are many modifiable lifestyle factors that could be the potential target of interventions for cardiometabolic health,” he says in the release.

“If a subgroup of people cannot benefit from exercise, other alternatives should be considered. That’s one of the most important implications of evaluating the heterogeneity of exercise interventions,” he states.

[Source: Brown University]