By Lindsay Wilson
Calories burned walking, working and living have a huge impact on energy expenditure and can be important for fat loss.
One of the most intriguing books on health I’ve ever read is Dan Buettner’s ‘The Blue Zones’. It tells the story of how together with National Geographic, and a bunch of scientists, he identified communities around the world where people lived particularly long and well. They were Ikaria (Greece), Loma Linda (US), Sardinia (Italy), Okinawa (Japan) and Nicoya (Costa Rica).
When they studied these communities to see what they had in common they came up with nine characteristics, the first of which reads like this:
Move Naturally: The world’s longest-lived people don’t pump iron, run marathons or join gyms. Instead, they live in environments that constantly nudge them into moving without thinking about it. They grow gardens and don’t have mechanical conveniences for house and yard work.
It’s a fascinating observation and provides an important bit of perspective for people thinking about weight loss. So often when we try to organise our efforts the focus is solely on three elements: diet, strength and cardio. This makes sense insofar as these are things we can easily measure and adapt, but they are certainly not the whole picture.
In this fifth section of The Fat Loss Framework we are going to talk about the importance of activity. We’ll look at how your work might affect your calorie expenditure, how walking more can help burn calories and why excessive sitting might not be great for your health.
1) Active people burn more calories
If you take three seemingly identical female friends (35 years, 170 lbs, 5’8, 2 hours exercise/week) and get them to stick to a 2,000 kcal/day diet (with decent macros) for four weeks they could easily lose 9 pounds, 5 pounds and 1 pound respectively.
What the scale tells us in this case is that seemingly similar people can have very difficult activity levels. If we then learned that one who lost 9lbs was a nurse, the 5lbs loser a busy lawyer and 1lbs loss from a desk bound designer we’d be a little less mystified.
Activity levels are colossally important for energy expenditure. We can define someone’s activity level as the ratio of total energy expenditure over a day to their basal metabolic rate (PAL=TDEE/BMR). The higher a persons activity level is the more calories they’ll burn, and the more they can afford to eat while losing weight.
As always I find this concept easier to explain visually:
In this graph we have total energy expenditure (y-axis) compared with activity levels (x-axis). What we see is that as activity levels rise so does total energy expenditure. And although the relationship isn’t perfect we can see that activity level predicts almost 40% of variation in expenditure among women, and close to 50% among men.
In this dataset the average person has physical activity level (PAL) of around 1.7. But when it comes to fat loss life is going to be much easier at 2.1 than it will be at 1.4. This is simply because you can get the job done eating so much more food.
The question this begs is can we increase our activity level?
As always, its complicated, because not everything about activity is within our control. As we discussed in the first section of this framework some people have naturally high ‘nonexercise activity thermogenesis’ (NEAT). That is some people move, fidget and have postural habits that simply burn more energy. A lot of this seems to be a mix of genetic and behavioural traits that are largely hard wired.
Of course this doesn’t mean we can’t nudge, design or even force our bodies to a higher activity level. We can. And that is what this section is all about.
Bottom line: people with active lifestyles use far more energy
2) Sedentary, active and vigorous living
At any point in the day you are burning energy, and every bit of it counts towards your caloric maintenance.
At compete rest, with no food to digest and at a comfortable temperature your caloric burn settles at your basal metabolic rate. This averages around 65 kcal/hour, and about 95% of people have a basal metabolic rate that falls between 45 kcal/hour (small, old, women) and 100 kcal/hour (big, young, men).
When you are sitting watching TV your probably burning +30% over this base level. Typing at a desk might be +50%, standing still its +70%, walking at 1 mph is +180% and jogging at 4mph is +400%.
Although you can burn a lot of calories doing cardio that doesn’t mean the rest don’t add up. In fact unless you do endurance training you can bet the house you burn far more energy at work than you do while exercising.
Here’s a graph using some data from the FAO to give you how it can all ad up.
The is stylized calculation of three people’s total energy expenditure over a day, all which have a BMR of 1,600 kcal/day. The ‘sedentary’ individual burns 2,400 calories a day, the ‘active’ one burns 2,800 calories and the one with a ‘vigorous’ lifestyle hits 3,600 calories.
Just by eye balling the chart you can see that the eating, personal care and leisure expenditure are all pretty similar. The elephant in the room is what type of work they do. The poor soul with the desk job burns just 800 calories during their shift, the standing job almost hits 1,200 and the physical worker clocks in above 1,900 calories a shift.
The issue of how much energy we expend at work it such a big deal, and so poorly understood, that I want devote a little more time to it.
Bottom line: every bit of daily movement adds to your total
3) Calories used during work shifts
Carefully controlled studies measuring how much energy people use at work don’t really exist, as you can’t really rap a metabolic ward around someone’s office. So to estimate how much energy a person uses during a shift we have to make do with occupation related MET values (metabolic equivalents).
These are good ballpark figures, but just take them as rough estimates as there will be a lot a variation within each occupation depending on how active each are. Here’s what the 8 hour calorie use looks like for the average US woman and man across varied occupations.
At the bottom of the pile we have desk jobs. The figures here are for people really stuck in their chair all day, people who can only work at a computer. As the work gets more active the calories go up.
Retail and eduction workers spend more time on their feet. Hospitality workers (waiters, chefs) are walking, moving and carrying light loads. For farming and manufacturing not only do people walk a lot, but they are lifting, bending and operating tools. Finally at the top of the pile we have construction. Someone who digs, lifts heavy loads and labours physically can expend up to three times more calories than a desk worker during a shift.
In the US, where there has been a large shift to a service based economy in the last four decades, a number of researchers believe the decline in workplace related energy expenditure is in fact a key driver behind the rise of obesity. The following chart comes from a fascinating study that estimated the trends in occupational related energy use over the last 50 years.
What the researches found was that the society wide shift to more sedentary work result in a drop of 140 calories per day for men and 124 calories per day for women. That might not sound like much, but dynamic modelling suggests a permanent shift like that alone is good for 12-14lbs of weight gain. The paper itself suggesting significantly more than this.
If you work long periods each day it is really worth thinking about your job effects you caloric burn. If like so many of us you are stuck in a desk for most of the day then its really worth asking if you can make some small changes to add a few hundred calories worth of activity into your work day. This is something we’ll get to ;-).
Bottom line: desk jobs use a thousand less calories than physical ones
4) Calories burned walking, standing and sitting
If your weight has been steady for a few weeks then the chances are you’ve been eating something close to your current maintenance. To get weight loss moving again you often have to change something. The standard approach to this in the fitness community is cut your calories or increase your cardio.
If you find doing either one of these particularly easy then great, they are relatively efficient. But if you struggle with both then its well worth asking yourself if you could move more during day to day life. The following chart uses some lab data to estimate how much energy we use per hour during some familiar activities.
Focusing on the middle frame we can see that when a 75kg (165lbs) is sitting watching TV they are typically using 100 calories per hour. Sitting typing uses just 9 calories more, while standing still is surprising efficient at just 119 kcal/h. In contrast the calories burned walking at just 0.4 mph are 170 kcal/hour. And at 1mph, a speed commonly seen on treadmill desks, the figure is 200 kcal/hour.
Because people have a the strange tendency to simply add exercise calories to there daily baseline I like to help people think in terms of net calories. That is, the calories that you’ll actually add to your daily total if you switch an hour of sitting to an hour of walking.
This is the same data as before, but you can see how much the ‘added calories’ context changes our view.
What this shows us is that if you are trying to burn more calories by getting out of your chair, then the numbers don’t really start to add up until you start moving your legs. In fact it turns out the human body is absurdly efficient at standing still, adding just 10 kcal/hour to sitting energy burn. In contrast for every hour someone walks slowly (1 mph) at a treadmill desk they are adding 100 kcal/hour to their expenditure. A truly meaningful amount if done regularly.
Bottom line: walking even slowly burns double the calories of sitting
5) The problem with sitting too much
The more time you spend sitting each day the lower your energy expenditure is likely to be, meaning you’ll need to eat fewer calories to create a deficit. However the caloric effects are just the tip of the iceberg when you start looking into the problems with sitting too much.
A 2012 meta-study looking at epidemiological studies covering almost 800,000 people found that:
Higher levels of sedentary behaviour are associated with a 112% increase in the relative risk of diabetes, 147% increase in the risk of cardiovascular disease, 90% increase in the risk of cardiovascular mortality and 49% increase in the risk of allcause mortality.
This mountain of epidemiological questions has led researches to uncover some of the mechanisms by which excessive sitting can mess with our bodies. These include promoting blood sugar spikes, impairing insulin handling, lowering muscle activation, disrupting sex hormones, aiding inflammation and messing with vitamin handling. Indeed when people say things like ‘sitting is the new smoking’ it isn’t all hyperbole.
Perhaps the most interesting study I’ve read on the risks of sitting too much assessed the relationship between sitting time and mortality among 17,000 Canadians. Their findings were particularly fascinating because they showed that sitting a lot is associated with dying more often even after you control for things like age, sex, BMI, smoking and exercise.
What we see from this data is that people who spend more than half their time sitting die far more often. The remarkable thing is that the jump in death rates occurs both for people that do exercise (active) and those that don’t (inactive). Indeed if you look at the absolute rates you’ll see that non-exercisers that rarely sit have much lower death rates than exercisers that are chairbound.
Because this is an epidemiological study we should avoid assuming this effect is purely causal. But as researchers understand more and more of the mechanism by which excessive sitting is disrupting health it would be foolish not question how long we spend sitting.
Bottom line: sitting more than half the day likely shortens life
6) Walking for health
If sitting shortens life then it seems logical walking must lengthen it? And basically it does. The evidence base for the health benefits of walking is robust.
In a 2008 meta-analysis of studies covering 459,833 participants regular walking was associate with a 31% lower risk of cardiovascular events and a 32% lower risk of death, with the ‘minimum dose’ being described as 3 hours a week (roughly 6 miles/10 km). Most interestingly the biggest effect was not seen by walking more (though that helped) but by walking faster (a 48% reduction in risk).
Hippocrates is supposed to have said “Walking is a man’s best medicine” around 2,400 years ago. And modern science just keeps on validating his view. Both walking more and walking faster seems to be protective. In terms of a ‘dose’ five 30 minutes walks per week at >3 mph is a great goal.
Bottom line: regular brisk walking is incredibly healthy
7) Walking for weight loss
Based on the data we’ve looked at so far you’d be forgiven for assuming that walking is the silver bullet for weight loss. It isn’t.
You see just like most other forms of exercise, walking has a sneaky habit of making you hungry. And when people put all their chips on exercise for weight loss the results are often disappointing. In fact a meta-study of walking based interventions averaging an extra 3,000 steps over 16 weeks showed mean weight loss of just 3 pounds (1.3kg). A very similar amount to a one year study giving people access to a treadmill desk.
The key takeaway from these studies is that exercise needs to support a smart diet. Most importantly you need to be aware of the potential for exercise to spike hunger causing you to eat back the extra calories you burn.
Personally I think walking more is a superb way to allow you to eat more while still losing fat. Moreover, the evidence that it can help people keep weight off is substantial.
Among members of the National Weight Control Registry (NWCR), a project that tracks people maintaining a weight loss of at least 13.6 kg (30 lb) for a minimum of a year, walking is the most popular form of exercise. As well as the biggest calorie burner.
These figures, from one of the first papers the NWCR did, show that people who lose significant weight and keep it off tend to be very active. And the biggest source of that activity is walking (around 1,000 calories a week). Among the people that participated in ‘medium’ or ‘heavy’ activity (a third in each case) the popular choices were cycling, lifting weights, aerobics and running.
Just let me hammer home this point?
At the time of this study the people involved had lost an average of 30kg (66lbs) and kept it off for 5.5 years! If you know anything about the phenomenon of weight regain, that generally starts around 6-8 months, you’d realise these people are all exceptional. And among these exceptional weight loss maintainers the leading exercise isn’t high intensity intervals or metabolic conditioning, it’s putting one foot in front of the other.
Bottom line: Walking is a powerful tool for keeping weight off
8) Designing activity into your day
The more active your lifestyle is the higher the calories you can eat while losing weight and the better your health outcomes are likely to be.
If you already have plenty of activity in your life already, in particular a physical job, then adding activity shouldn’t be a priority. You’ll be much better focusing on diet and working from your current expenditure. But if your stuck in a desk job, find yourself cutting calories uncomfortably low and aren’t keen on traditional cardio, then adding activity to your day can be an awesome tool for both weight loss and health. In particular if you have a really stagnant desk job I think it’s worth considering purely on a health basis.
Adding activity consistently a tricky problem. You can’t just say to yourself I’m ‘going to walk more’ and expect that to work. It’s a behavioural challenge that you need to think through. You need to consciously design activity into your day in a way that is as simple as possible.
I find the easiest way to approach this challenge is to dissect your day chronologically. The idea being to look for regular windows of opportunity in your normal work day when you have a chance to move more. Don’t worry about whether they are big or small windows, focus on how regular they are. If you can then trigger a movement behaviour in the same moment each day you have a great chance of making it a habit that can stick.
In the graphic above we are thinking about this problem on an hourly basis. Perhaps the three best options are your morning commute, lunch break and afternoon commute as these are largely unaffected by work responsibilities and split the day up well.
The reason I’m highlighting hourly options is that regular short bursts that break up long stints of sitting is where the main metabolic and health benefits seem to be. In fact an expert statement commissioned by Public Health England advises desk based workers to initially progress towards accumulating 2 h/day of standing and light activity (light walking) during working hours, eventually progressing to a total accumulation of 4 h/day! In their words:
To achieve this, seated-based work should be regularly broken up with standing-based work, the use of sit–stand desks, or the taking of short active standing breaks.
Together with other health promotion goals (improved nutrition, reducing alcohol, smoking and stress) they ask companies to explain to their staff that prolonged sitting (aggregated from work and in leisure time) may significantly and independently increase the risk of cardiometabolic diseases and premature mortality.
Basically, it seems that once you’ve been sitting down for an hour you’ve been sitting too long. I realise how incompatible this idea is with so many modern jobs but that’s simply where the evidence has taken scientists. Standing and walking desks are the obvious solution for people who need a computer for all their work, though success rates with their adoption seems to be quite variable. That said if you can get access to try one cheaply I’d highly recommend giving it a go.
Personally, I just try to create numerous routines that require moving throughout my day. Cycling the kids to school, walk for a coffee at 11, lunch time micro workout, afternoon stretch, afternoon school run . . . Any excuse to get away from the computer that monopolises my work day.
Our bodies are a masterpiece of evolution, but if we don’t move them we lose them. If you can create a culture of movement in your daily life it can improve your health, weight and quality of life.
Bottom line: Adding activity is a behavioural challenge
How you work has a large affect your calorie expenditure, walking is a great way to burn calories and excessive sitting probably isn’t great for your health. Adding activity to your day can start in the simplest of ways and build from there.
In the next section we’ll ask what the best cardio for fat loss is.