Persistence cardio muscle mass relationship

Does Long-Distance Running Burn Muscle Mass?

It’s a safe bet that the guys you know who are into bodybuilding are all terrified of running.

We don’t mean jogging, or hill sprints; we men long-distance, endurance running.

The guys who are serious about getting swole are usually completely averse to any kind of persistence training. They believe that any form of cardio that lasts longer than 15 minutes will serious eat into their gains. They hear “10km run”, and they picture a Kenyan marathon athlete; super shredded, but extremely thin with very little visible muscle mass. That’s the opposite of what they want, so they better skip the distance running, right?


The idea that long-distance running depletes muscle mass is a complete myth.

It is a widely held belief, but not because it is true. It is a widely held belief because the fitness industry needs you to believe that any exercise lasting longer than 45 minutes will kill your gains and turn you into a rake…unless you down a protein shake or two that is!

Well, you should be glad to learn that distance running is entirely compatible with muscle growth.

In fact, we’d go one further; if you want a truly lean, strong, aesthetic physique – if you really want to have that hunter-gatherer look – then distance running is downright necessary.


What The Science Says

We know that hunter-gatherers run much more frequently and for greater distances than most people living in the developed world today. We also know that they tend to have quite muscular, lean physiques and high levels of strength.

You’re probably also all familiar with what a guy looks like after a stint in the military, where they run every single day. They don’t tend to come back weak and small anyway.

So intuitively, we should know that regular aerobic exercise, even for prolonged periods, does not make you look like a marathon runner.

But we’re not interested in intuition and “seems right” reasoning.


How does running affect muscle mass


We don’t need to rely on it either; there’s plenty of hard scientific evidence proving that long-distance running does not eat into muscle mass in a significant way. What it does destroy at a rapid rate is body fat and glycogen stores.

The most convincing study we’ve ever seen on this topic is this one, published in 2009.

Here, researchers followed a group of ultra-endurance athletes as they ran for 62 days straight across Europe. They measured their body compositions at regular checkpoints, looking in particular at their fat free muscle mass and body fat.

Their findings are absolutely fascinating, and they should come as a big wake-up call for anybody who believes running and muscularity don’t mix.

If you look into the numbers behind their conclusion, you’ll definitely be impressed. 

During the 2-month long race, the athletes lost an average of 50% of their total body fat – 50%!

Incredibly, the racers had lost an average of 70% of their visceral fat stores by the half-way point. This is really interesting for anybody interested in maximizing longevity; visceral fat (the stuff around your internal organs) is the most harmful to health!

But for all this extreme weight loss, the runners only lost around 7% of their leg muscle mass. 

That’s 7% muscle wastage in the area being pounded non-stop, every day, for 2 months straight. 

It seems then that running long distances on a regular basis does not necessarily cause muscle mass loss.

We say “necessarily” because some studies have found that people who undertook a long-distance endurance race did lose significantly more muscle mass than they did body fat.

This study, published in the Journal of Sports Science & Medicine in 2006, found that “a multi- stage ultra-endurance run over 338 km within 5 days leads to no changes of body mass or body fat mass, but a statistically significant decrease of skeletal muscle mass of 0.63 ± 0.79 kg by the end of the race in well-trained and well-experienced ultra-endurance runners”.

Does that mean that one of these studies is wrong?

Is it just that the runners in the first race were genetic freaks?

No, not at all.

We just need to stop and think about what the second study is telling us.

It tells us that highly trained, experienced, ultra-endurance athletes lose (on average) less than 1kg of muscle mass during a 5 day event. It tell us that they do not lose any body fat.

So from that we can say that people who have extremely low body fat levels and a perfectly adapted musculature to long-distance running tend to lose some muscle mass over a 5 day event.

That really shouldn’t be surprising.

It should also give you some serious perspective if you worry about losing muscle mass by staying in the gym for an extra 30 minutes.

To lose 0.79kg of muscle mass from cardio, you have to be an ultra-lean endurance athlete who has just finished a 5 day, 338km race in an impressively fast time.

We think the extra 20 minutes on the bike after chest day isn’t anything to worry about. Not unless you already don’t have any body fat to lose and you’ve just been running for 3 days straight of course.


Running Is Vital For Strength & Conditioning

We think it’s pretty obvious that running doesn’t pose a serious threat to your muscle gains. Even ultra-low body fat athletes struggle to lose more than 0.7kg of lean mass during a week-long 338km race. If you have plenty of fat to lose and you’re running a reasonable distance (say less than 10km per day), you’ll be fine.

But we’d go one step further than simply saying “distance running is not harmful to muscle mass”.

We’re convinced that some kind of prolonged cardio is absolutely necessary if you really want to have that hunter-gatherer, warrior-like physique.

For one thing, prolonged aerobic exercise is the best way to improve your conditioning and recovery capacity. Having a well-oiled cardiovascular system will improve your performance in the gym, allow you to get more work done and therefore create more of a stimulus for growth going forward.

Imagine being able to plough through an extra 6-10 sets each week and recover more effectively from those sets. The extra load will definitely make a difference over the course of months and years.

But more important than that, prolonged, steady-state cardio is one of the most effective ways to put yourself into a deeper caloric deficit without exhausting your muscles for weight training.

Running 5km each morning lets you expend an extra 200-400 calories per day while still leaving you feeling fresh and strong when you get into the gym.

On top of that, running will work a plethora of different muscles without you really realizing it; you’ll be giving your abs, calves, glutes and obliques a very gentle workout each morning before you go ahead and blast them in the gym with heavy loads.

This is why people who combine heavy weight training with lots of prolonged cardio look like absolute animals. You know who we’re talking about:


Mike Tyson muscles with cardio


If you want a physique like this, then it’s time to stop swallowing the fitness industry dogma and embrace the obvious; looking like an animal requires you to TRAIN like one. Running is difficult, it’s tiring, and it requires real discipline. These are the things that make a great physique.

Start running today. You wont regret it!

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