Does Cardio Kill Gains? An Answer, According to Science

By many individuals’s lights, cardio is to muscle achieve what garlic farts are to a primary date. 

Kryptonite. 

Many guys and gals trying to construct muscle keep away from cardio like cigarette smoke, considering that even slightly whiff will kill their positive factors. 

Others take avoiding cardio to absurd extremes (utilizing the escalator as a substitute of the steps, for instance, or asking a buddy to stroll their canine so that they don’t “burn muscle”), and even many realized health consultants rail in opposition to the perils of cardio.

After all, many who take pleasure in lifting weights take a look at cardio like a drunk uncle who simply collapsed on their porch—a duty they know they ought to deal with however would relatively evade. 

Thus, when their favourite TikTok health tubthumper tells them that in the event that they wish to construct muscle, they should cease doing cardio, they soar on it.

The concept that cardio burns muscle is contagious: it gives a sCiEnTiFiC justification for shirking an exercise many individuals don’t like (cardio), it’s easy and catchy, and it even comprises a kernel of fact. And like many virulent health conventions, it’s additionally false. 

On this article, you’re going to be taught what scientific analysis has to say about questions like . . .

• Does cardio actually burn muscle? 
• Does fasted cardio burn muscle? 
• Do you have to do cardio whereas bulking?
• How a lot cardio is an excessive amount of? 

Allow us to start.

How Cardio Can “Burn” Muscle

When individuals say cardio “burns” muscle, what they actually imply is that cardio breaks down the contractile proteins that make up your muscle tissues.

They usually’re partly proper. Cardio can burn muscle . . . when you do virtually the whole lot incorrect together with your food regimen and coaching.

In a means, saying that cardio burns muscle, with no exceptions, is like saying that bank cards damage your funds.

Form of true for many individuals? Sure. 

Deceptive and facile to the purpose of being incorrect? Additionally sure. 

As you’ll be taught on this article, cardio received’t hamper your positive factors when you eat and prepare correctly. What’s extra, it’ll enhance your cardiovascular well being, scale back your danger of coronary heart illness, most cancers, and cognitive decline, make it simpler to get (and keep) lean, and probably even enhance your efficiency within the gymnasium. 

In different phrases, when you’re making the errors lined within the subsequent few paragraphs, you’ll achieve extra muscle and power when you cease doing cardio totally. Nevertheless, when you cease making these errors, you possibly can (and doubtless ought to) do cardio with out scuppering your positive factors. 

The highest six causes individuals suppose cardio burns muscle are as a result of they do. . . 

1. Cardio as a substitute of lifting weights.
2. Cardio as a part of a crash food regimen.
3. An excessive amount of operating.
4. An excessive amount of whole cardio.
5. An excessive amount of cardio at one time.
6. Exhausting cardio instantly earlier than, throughout, or after lifting weights.

Mistake #1: Doing cardio as a substitute of lifting weights.

Though many individuals blame cardio for inflicting muscle loss, a scarcity of weightlifting is extra precisely accountable.

For instance, one in every of many health gurus’s perennial purple herrings is to match photos of marathon runners and sprinters. “Hurr durr which might you relatively appear to be LOL? #nocardio #positivevibesonly #pumpedAF” This sophistic line of reasoning is the way you get photos like these: 

 

 

Their argument is that when you do conventional, low-intensity cardio (like marathon runners), you’re going to appear to be a scraggy wraith. In case you raise weights and do little or no cardio (like sprinters), you’ll appear to be a bodybuilder.  

After all, this inane argument ignores a number of details: 

1. Many endurance athletes don’t raise weights. Or in the event that they do, they accomplish that with mild weights, high-reps, and often or inconsistently. 
2. Most elite endurance athletes prepare far, excess of even aggressive leisure athletes. For instance, champion marathoners run as much as 160 miles per week—over 20 miles per day! That’s a far cry from what most individuals do to get match. 
3. Most elite endurance athletes have a borderline–unhealthy obsession with sustaining a low physique weight (particularly long-distance runners). They typically severely prohibit their calorie consumption to make sure they don’t achieve weight (both fats or muscle), as this reduces their efficiency.
4. Most sprinters, and positively those who appear to be IFBB execs, are on all types of steroids (Winstrol, testosterone, Deca-Durabolin, you title it). In addition they spend a very good chunk of their time lifting weights, as the extra muscle mass and power improves their efficiency, whereas this isn’t true for many endurance athletes. 

Mainly, the one factor these comparability photos show is that operating marathons, severely proscribing your calorie consumption, and never lifting weights is a recipe for staying small. 

The true query is what occurs if an endurance athlete begins consuming and lifting weights in a means that’s conducive to muscle achieve?

As a substitute of answering this query myself, I’ll let Ryan Corridor accomplish that. Corridor is a retired elite-level runner, who at the moment holds the U.S. file for the half marathon and is the one American to ever run a sub-2:05 marathon. Like most endurance athletes, Corridor didn’t raise weights, spent most of his time operating, and meticulously managed his calorie consumption to make sure he stayed skinny, mild, and speedy.

In 2016, Corridor retired from aggressive operating and began weightlifting. Not tottering on Bosu balls or doing planks until he was blue within the face—however heavy, compound weightlifting.

And right here’s what occurred:

“However doesn’t this show that cardio burns muscle? He solely received massive after he threw away his trainers!” 

Nope. 

Corridor nonetheless runs each week (with the quantity relying on his present objectives and schedule), and even often races. 

The lesson? 

Doing plenty of cardio on the expense of correct weightlifting can burn muscle, however that is a straightforward mistake to keep away from. As a substitute, raise weights too. (And earlier than you cry “steroids,” learn this article and ask your self if Corridor’s transformation raises any purple flags. Methinks not.)

Mistake #2: Doing cardio as a part of a crash food regimen.

Most individuals who do plenty of cardio aren’t elite endurance athletes like Ryan Corridor. As a substitute, the prototypical cardio junkie makes use of giant quantities of cardio together with a crash diet to drop extra pounds as quick as potential. 

And this works extraordinarily properly. 

For instance, a study revealed within the Scandinavian Journal of Drugs & Science in Sports activities had fifteen chubby males comply with a food regimen that supplied simply 10% of their calorie wants per day for 4 days. Right here’s the kicker: additionally they had them train 9 hours per day—eight hours (20 miles) of strolling adopted by 45 minutes of arm cranking. 

Certain as demise and taxes, they misplaced a boatload of physique fats—virtually 5 kilos in 4 days. 

The catch is that additionally they misplaced a couple of pound of muscle. 

After all, that is an excessive instance, however many individuals comply with a milder model of this protocol for a number of weeks or months, as a substitute of for 4 days. For instance, it’s not unusual to seek out individuals who lower their calorie consumption in half (a 50% calorie deficit) and do an hour or extra of cardio per day for a number of weeks to drop weight. 

Whereas they drop extra pounds shortly, additionally they often wind up shedding giant quantities of muscle and searching skinny fat.

And when this occurs, individuals typically blame cardio.

By no means thoughts the acute calorie restriction (which causes muscle loss even when you don’t train) or lack of protein. It was all cardio’s fault.

Mmmhmm. Certain. 

Similar to getting in debt is all the fault of your Amazon Rewards Visa. 

The underside line is that excessive calorie restriction of any type—whether or not it’s achieved by means of consuming much less, doing plenty of cardio, or a mixture of each—causes muscle loss, amplified a number of occasions over when you don’t raise weights.

That is the fault of reckless calorie restriction—not cardio.

Mistake #3: Operating an excessive amount of.

Does operating burn muscle? 

Form of. 

It’s true that of all of the sorts of cardio, operating appears to be uniquely inimical to gaining muscle (hypertrophy). 

Operating causes extra muscle injury than different types of cardio, like biking, rowing, and rucking, which interferes with muscle achieve in two methods: 

1. It considerably will increase muscle protein breakdown throughout and after runs, which makes it more durable to your physique to construct new muscle proteins.
2. It causes disproportionately extra fatigue than other forms of train, which may intervene together with your power coaching exercises. 

That mentioned, as our chum Ryan Corridor proves, this doesn’t imply any quantity of operating will damage your progress.

For example, one of many first studies on this subject had one group of individuals comply with a five-day-per-week power coaching program and one other group comply with the identical power coaching program in addition to three vigorous operating and three biking exercises per week. 

They discovered that the individuals who did each power coaching and cardio gained virtually the identical quantity of muscle because the individuals who solely lifted weights. Many different studies which have mixed operating and weightlifting have discovered the identical factor. 

Thus, the anecdotal and scientific proof is obvious: operating doesn’t burn muscle, however operating an excessive amount of can intervene together with your positive factors. You can avoid this, although, by limiting your weekly operating mileage and correctly planning your runs round your weightlifting exercises. 

Particularly, a very good rule of thumb is to do not more than two-to-three hours of operating per week, and ensure you do your operating and lower-body weightlifting on separate days. 

Mistake #4: Doing an excessive amount of whole cardio.

Even when you do most issues proper—you raise weights, eat sufficient energy and protein, get loads of sleep, and separate most of your cardio and weightlifting exercises—cardio can nonetheless retrench muscle achieve when you do an excessive amount of. 

Your physique can solely get well from a lot train per week, and when you’re already lifting weights three-to-five occasions per week, it’s solely logical that including an equal quantity of cardio on high of that is going to throw some sand in your gears. 

Some individuals misconstrue this to imply that “the extra cardio you do, the more durable it will likely be to construct muscle,” however that is incorrect. 

Research reveals that as long as you’re following a correct food regimen and strength training program, you possibly can achieve muscle simply as successfully doing just a few hours of cardio per week as you possibly can when solely lifting weights.

Doing greater than this doesn’t burn muscle, but it surely does retard muscle progress to a sure extent.

As soon as once more, although, the rub isn’t cardio as a complete—it’s merely doing an excessive amount of. The dose makes the poison (when you can name one thing that improves your well being in practically each means a poison). 

Mistake #5: Doing an excessive amount of cardio at one time.

Along with how a lot whole cardio you do per week, the period of your cardio exercises additionally impacts your means to construct muscle. 

Most studies have proven that an efficient strategy to keep away from the destructive results of cardio on muscle progress is to restrict most of your exercises to lower than an hour. Remember that doing greater than an hour doesn’t mechanically “set off” muscle breakdown, however merely will increase the danger of impeding your means to construct muscle. 

Additional proof for this technique comes from studies on pure bodybuilders, who typically do a number of 30-to-40-minute cardio exercises per week with out shedding any muscle to talk of. 

As Dr. Mike Zourdos, an Affiliate Professor at Florida Atlantic College puts it, “biking a pair occasions per week for half-hour at a reasonable depth has been proven to have completely no destructive impact on hypertrophy and power positive factors.”

Thus, as long as you retain most of your cardio exercises beneath an hour, you don’t want to fret about burning muscle. 

Mistake #6: Doing exhausting cardio instantly earlier than, throughout, or after lifting weights.

Lastly, the final mistake many individuals make when combining weightlifting and cardio is combining each sorts of coaching in the identical exercise. 

For example, many individuals will do half-hour or so of cardio instantly earlier than or after weightlifting, and others interweave bouts of weightlifting and cardio in the identical exercise (reminiscent of CrossFit or circuit coaching). 

None of those methods are preferrred.

Doing cardio instantly and even a number of hours earlier than lifting weights makes it difficult to carry out at your greatest within the gymnasium, which often ends in much less muscle progress over time. 

Doing cardio instantly after lifting weights is much less detrimental, however can even interfere with muscle progress by dampening a few of the anabolic (muscle-building) indicators from power coaching. 

We don’t have to get into the particulars of how this works, but it surely’s usually greatest to chorus from cardio instantly after lifting weights to permit the diversifications from power coaching to sink in. 

That mentioned, if the one time you are able to do cardio is true after lifting, don’t sweat it. Research shows that so long as you retain your cardio exercises pretty quick and low-intensity, this shouldn’t get in the way in which of muscle constructing. 

Lastly, mixing cardio and power coaching in the identical exercise (circuit coaching) will usually scale back your efficiency at each, thus lowering your positive factors over time. 

Once more, none of which means cardio burns muscle, however doing it on the incorrect occasions can meddle together with your physique’s muscle-building mechanisms. 

Bear in mind too that not all cardio is equally problematic. Strolling 10-to-20 minutes to the gymnasium is just not going to harm your positive factors. Doing an intense 30-minute HIIT exercise after which clomping from the treadmill to the squat rack will.   

The Proper Strategy to Mix Cardio and Power Coaching

So, does cardio actually burn muscle? 

No. 

In case you do cardio incorrectly, it could sluggish your fee of muscle progress by interfering together with your power coaching exercises and dampening the anabolic results of weightlifting. However it received’t make you lose muscle when you sidestep these blunders, which is straightforward to do.

Just like the bank card analogy, cardio could cause issues when you don’t know the way to use it correctly. Use it properly, although, and you’ll reap many rewards. 

Right here’s how:

1. Prioritize low-impact types of cardio like biking, rowing, snowboarding, and rucking.
2. Restrict the quantity and period of your cardio exercises to not more than 30-to-45 minutes per cardio exercise and two-to-three hours of whole cardio per week.
3. Separate your cardio and power coaching exercises by as a lot time as potential, and attempt to keep away from coaching the identical muscle group with each weightlifting and cardio on the identical day (reminiscent of squats within the morning and operating within the afternoon).

Do these three issues, and cardio ought to have kind of no destructive results in your means to achieve muscle. 

In the end, cardio doesn’t must intervene with muscle achieve when you implement it correctly. At backside, the explanation cardio has earned a nasty rap is because of person error, not as a result of cardio kills your positive factors.

If you wish to be taught extra about the way to mix power coaching and cardio with out interfering with muscle achieve, take a look at this Legion article: 

Concurrent Training: The Right Way to Combine Cardio and Strength Training

FAQ #1: Does fasted cardio burn muscle?

Fasted cardio entails deliberately doing cardio after your final meal has totally digested (often no less than five-to six hours or so). 

Whereas fasted cardio does increase fats burning throughout your exercise, it causes two issues: 

1. You burn less fat throughout the remainder of the day, which implies you lose the identical quantity of whole physique fats over a 24-hour interval as you do after fed cardio.
2. Your danger of muscle loss rises.

The principle motive fasted cardio could cause muscle loss is that it shortly depletes muscle glycogen ranges, and when this occurs, the physique begins to interrupt down protein (muscle) for power. 

Nevertheless, you usually must do a good quantity of cardio—no less than 60 minutes or extra—to deplete glycogen ranges. Thus, your danger of shedding muscle after a brief ~30-ish minute fasted cardio exercise is minimal. 

If you wish to be taught extra in regards to the execs and cons of fasted cardio and the one scenario the place it may be helpful, take a look at this text: 

What Is Fasted Cardio and Can It Help You Lose Weight?

FAQ #2: Does high-intensity cardio burn muscle? 

No, no less than not any greater than common cardio, as long as you aren’t making the errors listed above. 

Whereas some individuals declare that high-intensity cardio is much less prone to burn muscle, the proof for that is spotty. Some studies present that high-intensity cardio interferes with muscle progress greater than conventional, low-intensity cardio, and others show the alternative.

Whereas research haven’t supplied a definitive reply to this query, there’s good motive to suppose that high-intensity cardio could also be barely extra prone to intervene with muscle progress than low-intensity cardio. The principle motive for that is that high-intensity cardio tends to trigger extra muscle damage and fatigue than low-intensity cardio, which may intervene together with your power coaching exercises and scale back muscle achieve over time. 

Thus, high-intensity cardio doesn’t burn muscle, however you’re in all probability higher off choosing low-intensity cardio more often than not in case your predominant purpose is to get swole.

FAQ #3: How a lot cardio is an excessive amount of?

There’s no laborious and quick rule about how a lot cardio you need to do, as the reply depends upon your objectives, preferences, and restoration skills. 

That mentioned, in case your main purpose is constructing muscle, listed here are just a few guidelines of thumb that are likely to work properly for most individuals: 

• Restrict the time you spend doing cardio to not more than half the period of time you spend weightlifting every week. For example, when you raise weights for 4 hours per week, don’t do greater than two hours of cardio.
• Restrict the period of most of your cardio exercises to 30-to-45 minutes, solely doing greater than this when you take pleasure in it or if you wish to considerably enhance your endurance.
• Don’t do multiple HIIT cardio exercise per week. If you wish to do extra cardio than this, do the remainder of your exercises as low-intensity cardio.

FAQ #4: Do you have to do cardio whereas bulking?

You don’t have to do cardio whereas bulking, but it surely’s a good suggestion for a number of causes: 

• Cardio offers many well being advantages which might be tough to get from weightlifting alone, reminiscent of larger decreases in blood stress and ldl cholesterol and enhancements in blood vessel well being.
• Cardio could enable you recover faster between units throughout your weightlifting exercises, which may enhance your positive factors over time. 
• Cardio improves your physique’s means to burn fats, which can make it simpler to lose fats when it’s time to start out cutting once more.
• Likewise, doing cardio whereas bulking helps you keep within the habit of doing cardio, which makes it simpler to leap again into it once you wish to get lean once more.
• Cardio will be enjoyable. In case you take pleasure in it, there’s no motive to keep away from mountain climbing, biking, snowboarding, and even some operating whereas bulking, so long as you don’t make the errors listed earlier on this article.