Do you need cardio if you lift weights?

The evidence-led answer

NST verdict

If you lift weights regularly, you are already doing something real for your heart. Strength training is independently linked to a lower risk of dying from cardiovascular disease and other causes, and a major heart health body considers it a safe, effective way to improve cardiovascular health. But it is not a full substitute for cardio. Aerobic training does considerably more for your cardiorespiratory fitness, a strong predictor of long term health, and in a head to head trial, only the group doing both lifting and cardio lowered their blood pressure. The largest reductions in mortality risk come from doing both kinds of exercise. So keep lifting, and add some cardio. You do not have to choose.

Is lifting good for your heart?

Yes, genuinely, and on its own. A pooled analysis of 16 long term studies found that muscle strengthening activity was independently associated, on top of any aerobic exercise, with roughly a 10 to 17% lower risk of all cause mortality, cardiovascular disease, total cancer and diabetes. The American Heart Association's 2023 scientific statement concludes that resistance training is a safe and effective way to improve cardiovascular health in adults with and without cardiovascular disease, and that it improves a range of heart disease risk factors.

Most of that benefit comes from a modest amount. The mortality and cardiovascular associations were J shaped, with the biggest risk reduction at around 30 to 60 minutes of muscle strengthening activity per week. That is the health dose. It is separate from how much training volume it takes to build muscle.

Where lifting falls short of cardio

Two places. Cardiorespiratory fitness: aerobic training raises your VO2max, your body's capacity to use oxygen, far more than lifting does. In a time matched 8 week trial, aerobic only training raised VO2max by about 7.7 mL/kg/min, combined training by about 4.9, and resistance only training by little. Cardiorespiratory fitness is one of the strongest predictors of long term mortality, so this gap matters.

Blood pressure: in the same trial, neither resistance only nor aerobic only training lowered blood pressure over the 8 weeks; only the combined programme did, and combined training also produced the best overall profile across blood pressure, fitness, strength and lean mass. And in the long term data, the largest reductions in mortality come from people who do both muscle strengthening and aerobic activity.

So how much of each?

You do not have to pick a side. Keep lifting for strength, muscle and its own cardiovascular benefit. Then add aerobic work: general public health guidelines suggest roughly 150 minutes a week of moderate activity, brisk walking, cycling, jogging, rowing, a class, or about 75 minutes of vigorous activity, split across two to four sessions, alongside your two days of strengthening. If your time is limited, combined sessions, some lifting plus some cardio in the same workout, are an efficient way to get both.

What this means in practice

Keep your lifting. It is not "wasted" heart health time; it lowers your risk independently, and a modest weekly amount captures most of that. But schedule some cardio too: a couple of dedicated sessions a week, or cardio bolted onto the end of lifting days, aiming loosely at the 150 minutes moderate guideline. If you genuinely cannot fit both, prioritise not dropping either entirely, since even a small amount of each beats a lot of one and none of the other. And if you have known heart disease, symptoms like chest pain, breathlessness or palpitations, or major risk factors, check with a doctor before adding hard cardio. This is general information, not medical advice.