New systematic review maps aerobic and resistance training for cardiovascular risk

Most people who train in the gym assume the heart-protective effects of lifting simply rise with effort: more sessions must mean more protection. That sort of straight-line thinking broadly fits endurance exercise such as running or cycling.

Fresh evidence suggests resistance exercise follows a different pattern, and a new systematic review has now outlined what that pattern looks like.

The researchers’ findings on when you train and how you pair different exercise types challenge long-standing assumptions that have rarely been properly tested.

Looking deeper at exercise in Dr. Fangchao Liu’s systematic review

Dr. Fangchao Liu, an epidemiologist at Fuwai Hospital within the Chinese Academy of Medical Sciences, led a wide-ranging new analysis examining exercise in relation to cardiovascular health.

Rather than focusing only on how many events occur, the review also considers what is changing within the body. Existing physical activity guidelines still serve as the starting point.

Those guidelines advise doing 150 to 300 minutes of moderate-intensity aerobic activity each week. For vigorous-intensity activity, the recommended range is 75 to 150 minutes per week.

Alongside that, the guidance also advises muscle-strengthening exercise on two days per week.

What has largely been lacking is finer detail about dose and combinations. Until this review, no earlier synthesis had set aerobic training, resistance training, and the two together side by side, while looking at both population outcomes and underlying physiological effects.

Cardio’s biggest heart benefits

On aerobic exercise, the review broadly supports earlier research while adding important detail. Aerobic activities-such as running, cycling, brisk walking, and swimming-reduce cardiovascular risk in a non-linear way.

Doing more still helps, but the most dramatic improvement tends to happen right at the start, when someone who is inactive begins to do any activity at all.

Where this work adds clarity is in charting where the benefit curve begins to level off and where improvements can still accumulate, using objectively measured movement rather than people’s own estimates.

In practical terms, those who move very little stand to gain the most simply by moving away from zero.

When strength training helps most

Weight training shows a different dose–response. For resistance training, the association with cardiovascular risk forms a J-shape.

As weekly minutes increase, risk falls, reaching its lowest point at roughly 40 to 60 minutes per week, before edging upwards again. The “sweet spot” appears relatively narrow.

In effect, two brief lifting sessions each week seem to capture the cardiovascular benefits without drifting into the range where the evidence begins to raise caution.

The authors also stress the limits of the current data. Compared with moderate lifters, there is less evidence available for people who lift at higher volumes, and the research base is not yet strong enough to define a firm upper limit.

The combo advantage

The most striking result emerges where the two styles meet. When aerobic and resistance training are combined, the outcomes are better than with either approach on its own.

Aerobic exercise challenges the heart, lungs, and metabolic systems. Resistance work alters muscle mass and body composition, and affects how the vascular system responds to pressure when the body is under load.

When these adaptations are paired, they appear to add together rather than simply duplicate one another. For the research team, that synergy is not a minor extra-it becomes the central recommendation.

Mixing workouts delivers bigger gains

The timing of training may matter as well. Objective activity measurements indicate that doing aerobic exercise in the evening is linked with greater cardiovascular benefit than performing the same workout earlier in the day.

Other studies point in the same direction. One 2024 paper that followed adults living with obesity reported the lowest rates of cardiovascular events and small-vessel damage among those who exercised in the evening, compared with morning or afternoon exercisers within the same cohort.

Even so, the biological explanation is not settled. Circadian rhythm, daily blood pressure variation, and the way glucose is handled overnight could all plausibly contribute. However, the timing signal itself appears consistent.

Weekend workouts still help

For anyone who cannot fit exercise into most days, the review offers reassuring news. Compressing the week’s activity into one or two sessions-the “weekend warrior” approach-still meaningfully reduces cardiovascular risk.

A 2017 study that followed more than 63,000 adults found that people exercising only at weekends experienced almost the same reductions in cardiovascular mortality and all-cause mortality as those who spread exercise across the week.

In other words, total weekly volume seems to matter more than whether those minutes are distributed evenly.

What happens inside the heart

The physiological discussion is particularly specific. Consistent aerobic training increases the heart’s capacity to extract oxygen from the blood and improves the way working muscles utilise that oxygen.

It also encourages the development of new capillaries around the heart-small “detour” vessels that can help keep tissue alive if a major artery becomes narrowed.

Active muscle tissue releases exerkines, chemical messengers that circulate in the blood and are thought to signal other tissues to form new blood vessels, reduce inflammation, and support repair.

Reductions in blood pressure, improvements in insulin sensitivity, and healthier blood vessel walls are presented not as vague claims but as measurable shifts that can be seen in imaging and laboratory results.

These kinds of measurable effects are more firmly established for aerobic activity than for resistance exercise, which is why the J-shaped pattern for strength training comes with an asterisk.

Much of the research underpinning resistance training relies on self-reported behaviour rather than objective tracking, limiting what can be said about the highest training volumes.

So while the cautionary trend at higher lifting volumes should be taken seriously, it remains early rather than definitive.

A more personalised exercise future

Overall, the review provides a sharper picture than earlier summaries. It indicates that combining aerobic exercise with resistance training offers more protection than either approach alone.

It also reinforces that the largest improvements occur in people who start from inactivity, and it shows that timing and weekly exercise patterns can influence outcomes in ways older guidelines did not capture.

As a result, exercise prescription may be due for an update. Broad “minutes per week” targets could increasingly be replaced by more personalised plans based on someone’s risk profile, their schedule, and data from wearables.

For people already living with cardiovascular risk factors, becoming more active can deliver larger benefits-but it also raises the importance of getting the dose and type of exercise right.

The research team argues that the next phase should focus on identifying key biomarkers that can indicate when training is protecting the heart and when the load may be tipping into “too much.”