Can you do cardio and still build muscle?

Yes. In the studies, people who added cardio to the same lifting program built about the same muscle as people who only lifted.^[1] On average, their strength grew about the same too.^[1] What took a small hit was explosive power: how high you can jump, or how fast you can push.^[1][2]

Cardio means aerobic or endurance exercise: running, cycling, rowing, intervals. Doing cardio and lifting in the same program is called concurrent training. The interference effect is the idea that the cardio blunts what the lifting builds.

The fear isn't made up. Some studies did find a cost to leg strength. In one analysis, it showed up in people who already trained, mostly when cardio and lifting shared a session.^[3] It found no leg-strength cost in beginners.^[3] Another found a small cost in men, beginners included.^[4]

Walking counts as cardio, too. The health guidelines list it as aerobic activity.^[5] The last article, daily steps, covered how much of it to aim for. This one covers the harder stuff, and whether it costs you muscle.

Why it matters

The real risk for a beginner is believing the myth. Skip cardio to "protect your gains" and you give up something health guidelines ask every adult to do.^[5] The World Health Organization (WHO) links physical activity in adults with a lower risk of early death and of dying from heart disease.^[5] The same goes for high blood pressure, type 2 diabetes and some cancers.^[5] It also links activity with better mental health, thinking and sleep.^[5]

You'd also miss the fitness part. In the newest summary of the research, adding cardio to lifting gave better aerobic fitness than lifting alone.^[6] Aerobic fitness is how well your heart and lungs keep you going on a long effort.

The opposite mistake costs less, but it's real. Doing cardio and lifting in the same session is where the costs showed up in the studies: in explosive power, and in leg strength for people who already trained.^[1][3] That's easy to fix once you know.

What the research says

A few terms first. A meta-analysis pools the results of many studies on the same question into one estimate. Hypertrophy means muscle growth. Maximal strength is the most weight you can lift once, called your one-rep max (1RM). Explosive power is how fast you produce force. Researchers measure it with jump height and fast pushes on a leg press.^[1]

Most studies below compared the same thing: a lifting program with cardio added, against the same lifting program without it. The order studies are different. They compared lifting first with cardio first. So the question is "does adding cardio cost me anything?" It isn't "cardio or lifting?"

Muscle growth: no measurable difference

Moderate evidence. It's one good meta-analysis that measured whole muscles directly.

A 2026 overview pooled 17 meta-analyses covering 144 studies. It found that lifting plus cardio gave strength, power and muscle gains comparable to lifting alone, and better aerobic fitness.^[6] Moderate evidence. It pools earlier analyses, so it's mostly the same data seen from higher up, not new proof.

A closer look at single muscle fibres

Muscles are made of thin cells called fibres. One analysis looked at fibre size, measured from biopsies (a tiny piece of muscle taken out with a needle).^[7] It pooled 15 studies and found a small possible cost from adding cardio. The result sat right on the line of statistical chance.^[7] For one type of fibre, the cost was larger when the cardio was running, but only 3 studies used running.^[7] The authors called it "preliminary."^[7]

Limited evidence. Treat this as a hint, not a finding. It came from the same research team as the large analysis above.

Explosive power took a small hit

This is where adding cardio did cost something. In the large analysis, explosive power gains were a little smaller with cardio added: a small effect.^[1] An older 2012 meta-analysis of 21 studies found the same direction. Lifting alone built more power than lifting plus cardio.^[2] Moderate evidence.

The cost was bigger when cardio and lifting were in the same session (20 minutes apart or less). When the two were at least 3 hours apart, it didn't show up.^[1] Limited evidence. It's a subgroup result, and close to the line of chance.

For most beginners, jump height isn't the goal. If you play a sport where it is, this part matters more.

Strength: fine on average, with one exception

Mixed evidence. The average cost to maximal strength was about zero.^[1] But one group showed a dip.

A 2021 meta-analysis of 27 studies looked at leg strength (leg press and squat 1RM) by training status.^[3] In people new to training, leg strength grew about the same with or without cardio.^[3] But a 2024 analysis of 59 studies, most of them in people new to lifting, found a small leg-strength cost in men and in beginners.^[4] Mixed evidence. In people who already trained, leg strength grew a bit less with cardio added.^[3] The authors called that dip "moderate."^[3]

In trained people, the dip showed up when cardio and lifting were done less than 20 minutes apart. When they were more than 2 hours apart, the studies couldn't tell it apart from no effect.^[3] Limited evidence. It's a subgroup. Also, "trained" in this analysis included endurance athletes, not only lifters.^[3]

The 2024 analysis also split the results by sex. The leg-strength cost showed up in men, not in women.^[4] Limited evidence. There were fewer studies in women. And there was too little data to say anything about muscle size by sex.^[4] It's not enough to write a separate rule for women.

Running or cycling: the studies disagree

Mixed evidence. Here's what each analysis found.

• The 2012 meta-analysis found that running, but not cycling, cut into muscle and strength gains.^[2]
• The 2022 analysis, with 24 cycling studies and 16 running studies, found no difference between them.^[1]
• A 2018 analysis looked at HIIT (high-intensity interval training: short hard efforts with rest in between). HIIT plus lifting built about the same muscle and upper-body strength as lifting alone. Leg strength dipped slightly.^[8] There was a trend for cycling HIIT to hurt leg strength more than running HIIT, a hint and not a finding.^[8]
• The running signal in the fibre study rests on just 3 studies.^[7]

So no machine wins. Older evidence pointed one way, a newer analysis found no difference, and interval studies hinted the other way.

How much cardio is too much?

Nobody has found a tested limit. In the 2022 analysis, people who trained more than 5 times a week did about the same as people who trained less often. That count was cardio and lifting sessions combined.^[1] The 2012 analysis found that more frequent and longer cardio went with smaller lifting gains.^[2] But that was a pattern across studies, not a test of a set amount. Limited evidence.

Lift first, or cardio first?

If you do both in one session, lifting first gave a small edge in leg strength. One meta-analysis of 10 studies found about 7% more leg strength gain with lifting first.^[9] Another found about 4 kg more on a leg 1RM over the studies.^[10] The 2026 overview found no clear effect of order, though its results leaned toward lifting first.^[6] Mixed evidence. Two older analyses found a small edge. The newest overview couldn't confirm it, but leaned the same way.

Order made no difference to aerobic fitness in either analysis.^[9][10] In the first one, it made no difference to muscle growth or body fat either.^[9] Limited evidence for the growth part, as only a few studies measured it.

What health guidelines ask for

The WHO guidelines for adults aged 18 to 64 ask for both kinds of exercise each week:^[5]

• 150–300 minutes of moderate aerobic activity, or 75–150 minutes of vigorous activity, or a mix of the two.
• Muscle-strengthening work for all major muscle groups on 2 or more days.

Expert consensus. This is the panel's view, not a tested finding. WHO rates both as strong recommendations, built on systematic reviews of the research.^[5]

Walking is on WHO's list of aerobic activities, next to running, swimming and cycling.^[5] Activity at work, at home or while getting around all counts toward the target.^[5] And doing some is better than doing none.^[5]

How to apply it

These steps follow from the studies above, except step 5. Step 5 is coaching practice, not a tested finding.

1. Keep your lifting program and add cardio on top. That's the setup the studies tested, and muscle growth came out about the same.
2. Pick the cardio you'll keep doing. Running, cycling, rowing, swimming or brisk walking. The studies disagree on which costs less, so choose by what you enjoy and can fit in.
3. Count your walking. It's aerobic activity, and the minutes add up toward the weekly target.
4. If leg strength or jumping matters to you, keep hard cardio away from leg days. Put it on another day, or hours apart. If they share a session, lift first.
5. Don't let cardio crowd out your lifting sessions. If your week gets tight, keep the lifting days and trim the cardio.

A worked example

Ana weighs 70 kg and lifts three days a week: Monday, Wednesday and Friday. She wants to build muscle and also meet the cardio guideline.

• Walking: a 20-minute brisk walk on the way to work, 5 days a week. That's 100 minutes.
• Cycling: a steady 25-minute ride on Tuesday and Saturday. That's 50 minutes.
• Total: 150 minutes a week, the low end of WHO's moderate range, if her walks and rides are moderate effort.

Her lifting doesn't change. On Monday she squats 60 kg × 8, 8, 8, as planned. Next Monday she aims for 60 kg × 9, 8, 8.

One week she can only make the gym once, on Saturday. She lifts first, then rides for 20 minutes. Lifting first is the order that gave the small leg-strength edge in two analyses, and the ride still counts.

This is where practical and best-on-paper can differ. On paper, cardio on separate days from leg training is the safer pick for strength. In practice, the leg-strength dip in the studies was small, so fit cardio wherever your week allows.

Two questions this article leaves alone. Whether cardio helps with fat loss is covered in energy balance. How fast the muscle itself comes is covered in how fast you can build muscle.

Common mistakes

Skipping cardio to protect your gains. "Cardio kills gains" is a common gym saying, and it sounds plausible. But in the studies, adding cardio made no measurable difference to muscle growth.^[1] Fix: do the cardio, and keep lifting as planned.

Choosing a machine because of a rule you read. "Only cycle, never run" goes further than the evidence. One older analysis found running cut into gains, but the largest newer one found no difference.^[2][1] Fix: pick the cardio you'll actually do.

Hard cardio in the same session as heavy legs. It's convenient to do everything in one visit. For people who already trained, that's where the leg-strength dip showed up.^[3] Fix: if strength matters, lift first or split them up.

Not counting walking. People assume cardio means sweating on a treadmill. Walking is on WHO's list of aerobic activities.^[5] Fix: count your brisk walks toward the weekly minutes.

How Gymbers fits

Cardio adds to your lifting, so the lifting is what to keep an eye on. The Gymbers app logs the weight and reps for every set, and last session's numbers sit beside each set. Add cardio, and your next sessions show whether your lifts keep moving. Steps sync from Apple Health (iPhone) or Health Connect (Android) into the same log. The default daily step goal is 10,000, and you can change it.