How Sedentariness Affects Muscle Growth & Fat Loss (Even for People Who Exercise)

It’s fairly well established that if you spend most of your time being sedentary (aka sitting), then you’ll burn fewer calories, and you may find yourself getting out of shape, gaining weight, and losing muscle over time. Perhaps that’s why so many people who work desk jobs complain of being “skinny-fat.”

The solution to sedentariness is typically thought to be doing exercise, and that’s true. Exercise is the best way to specifically address these issues:

• The best way to improve your cardiovascular fitness is to do cardio.
• The best ways to gain/maintain muscle are to lift weights or do callisthenics.

The other obvious piece to this puzzle is getting your calorie intake right. If you’re eating more calories than you’re burning, you’ll gain weight. Or, if you’re eating fewer calories than you’re burning, you’ll lose weight.

• Lifting weights while eating in a calorie surplus (bulking) is the best way to gain muscle.
• Lifting weights while eating in a calorie deficit (cutting) is the best way to lose fat while maintaining your muscle.

So you might imagine that by doing cardio, lifting weights, and keeping your calories under control, you can maintain good health and body composition. And that’s true. But even when we control for all of that, sedentariness is still a factor.

Even for people who regularly exercise, eat well, and eat the correct amount, spending too much time sitting still has a negative impact on our body composition.

What is Sedentariness?

Sedentary is a fancy way of referring to the amount of time we spend sitting. In the research, though, it’s used a little bit more broadly, referring to periods of time when we don’t burn many calories. That means that sitting, lounging, and lying down all count as being sedentary.

If we look at the exercise guidelines given by the World Health Organization, we get a recommendation to do at least 1.25–2.5 hours of exercise per week, depending on how intense that exercise is.

The thing is, as more research is done, it’s becoming clear that the amount of exercise we do is separate from the amount of time that we spend sedentary. Even if you exercise, how much time you spend sitting vs walking can still have an impact on your muscle growth and fat loss.

What I mean is, even if you exercise, it’s still possible to be considered sedentary. So in addition to exercising, we need to make sure that we’re spending enough time on our feet. One way to do that is to spend more time standing, but an even better way seems to be spending more time walking.

How Much Does Walking Affect Body Fat?

Eric Trexler, PhD, founder of the Monthly Applications in Strength Sports research review, crunched the numbers from a study looking at how sedentariness affected body composition in various athletes. He found that sedentariness was responsible for around 4% of the body-fat differences between athletes.

Looking at these numbers, the body composition researcher, Eric Helms, PhD, said, “Now that’s not nothing, but it also shows that other factors like training, nutrition, sleep and genetics play much larger roles.” And that’s a good point. These are not huge numbers. If you want to build muscle and lose fat, walking is one of the finer details, not the foundation.

On the other hand, the differences in fat were largely in visceral fat (aka trunk fat), the fat that wraps around our organs. This is the type of fat that’s most strongly associated with poorer health outcomes. By reducing our visceral fat, we can improve our health. Walking is great for that, and the body composition benefits come as a welcome bonus.

How Much Does Walking Affect Muscle Growth?

Dr Trexler’s analysis of the above study found that 3% of the differences in muscle mass between people can be explained by how sedentary they are. That roughly lines up with the differences in fat, meaning that even if you don’t lose or gain weight, it’s reasonable to assume that walking should help you become slightly leaner and more muscular.

Again, compared to other factors, such as lifting weights, diet, sleep, and genetics, it’s not a huge factor. But it’s something, and it comes along with several other benefits, most notably improved overall health.

How Many Steps Should You Take Per Day?

If we look at a couple different studies, it seems that getting at least 7,000 steps per day seems to result in the best health outcomes and body composition, including more fat loss, more muscle mass, better heart health, and better adaptations from working out (study, study).

My business partner, Jared, is a desk worker, he’s a dad with 3 young kids, and he lifts weights 3–5 times per week. He was averaging 2,000–3,000 steps per day. Even with kids running around the house, even with regular exercise, he was only walking half as much as he should have been.

I also work a desk job, I’m also a dad (with a toddler), and I lift weights 3 times per week. But I also have a dog that I walk in the morning and evening. That 10-minute walk in the morning combined with a 20-minute walk in the evening brought my daily step count up to 6,000 steps per day. And by extending my morning walk to 15–20 minutes, I was able to routinely get 7,000 steps per day.

My wife is on still on maternity leave, she spends the day hanging out with our son, runs errands, and manages stuff around the house. Without adding in any extra walking, she was already getting 5,000–8,000 steps on an average day, with more like 9,000–14,000 on weekends. She because she already spends so much time on her feet, she isn’t sedentary and doesn’t need to offset her lifestyle with extra walks.

For another example, my wife and I took a brisk 30-minute walk to the beach, read for an hour, and then walked back home. That hour of walking gave us around 10,000 steps. These extra steps can then be averaged into the week. So although daily steps are important, if you have some extra time on the weekends, that’s a good way to boost your weekly average.

In the past, one of my favourite ways to walk was to pop in some headphones and listen to audiobooks while walking to the gym, getting groceries, or walking around town. It was an enjoyable way to get things done while also getting some good walking in.

This lines up with the research. Dr Eric Helms recommends that people who spend a lot of their time sitting add in at least 40 minutes of walking per day. He also recommends splitting that 40 minutes up into two separate walks. So, for instance, maybe that’s a 20-minute walk in the morning and then another 20 minutes in the evening. Not only would that give you enough daily steps, but you’d also get a bit of sunshine in the morning and evening, helping you to get enough vitamin D.

What’s the Best Way to Measure Your Steps?

A pedometer is a device used to measure how many steps we take. When I told my wife that I wanted one, she squinted at me and told me that it was a dumb idea. I was confused. I explained that a pedometer would help us figure out if we’re taking enough steps per day to be healthy. Then it was her turn to be confused. “What does measuring farts have to do with how many steps we take?”

These are the sorts of misunderstandings that can happen when living in Mexico. Not so different from when she would call our son her “pedacito” and I thought she was calling him her “little fart.”

Anyway, this whole idea that we should be walking a given number of steps per day is coming from studies that use pedometers, meaning that if we measure our steps the same way, we can be confident that we’ll get the same outcomes.

There are pedometer apps that you can download on your phone, and those are certainly better than nothing, but none of them are as accurate as a dedicated pedometer. I chose this simple iGANK pedometer (affiliate link). It’s only $17.

Summary

By making sure that we’re spending enough time walking, we can improve our muscle growth, fat loss, and health. 7,000 steps per day is probably enough to get all of those benefits. If you’re active during the day, you may exceed that step count already. For a desk worker, taking two 20-minute walks per day is usually enough.

The next thing to keep in mind is that sedentariness is a relatively minor factor in determining our body composition, explaining just 4% of the differences in body fat between people, just 3% of the muscle mass. If you want to lose fat and gain muscle, the most important things are:

• Following a resistance training program that stimulates muscle growth, ideally hypertrophy training.
• Eating the correct amount of food. If you’re trying to gain muscle, eat enough food to gain weight. If you’re trying to lose fat, eat in a calorie deficit so that you lose weight.
• Eating enough protein. 0.8–1 grams of protein per pound body weight per day is a good minimum when trying to gain/maintain muscle mass. So for someone weighing 180 pounds, that’s at least 144–180 grams of protein per day.
• Getting enough good sleep. Getting at least 7–9 hours of good sleep each night is an important part of building muscle and losing fat.

If you want a customizable workout program (and full guide) that builds in these principles, check out our Outlift Intermediate Bulking Program. Or, if you’re still skinny or skinny-fat, try our Bony to Beastly (men’s) program or Bony to Bombshell (women’s) program. If you liked this article, you’d love our full programs.