Tag Archives: activity

Our toxic activity environment, and what you can do about it.

Posted on March 9, 2015 | 1 comment

Last week I introduced the idea that we live in a “toxic environment,” which provides easy access to high-calorie, unhealthy, inexpensive food and promotes physical inactivity. The focus was on the toxic food environment, so now it is time to explore our toxic activity environment and how you can modify it to increase your activity, which can help you lose weight.

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The environment affects our physical activity on several levels. The built environment refers to the layout of our communities, including roads, sidewalks, availability of public transportation, where homes and businesses are located, and even the design of buildings. If you live in a mixed-use area in which there are lots of well-maintained sidewalks that connect your home to schools, parks, churches, restaurants, shops, and businesses, the built environment is likely to support more activity. In larger cities, an effective public transportation network can increase your activity.

However, many people live in areas where there aren’t sidewalks or, if there are, the distances between destinations are too far to make walking convenient. Or they live in a neighborhood that is separated by distance or geography (a busy road, perhaps) from other places they go. Even when sidewalks are present, using them may be challenging due to poor maintenance, automobile traffic, or dangerous road crossings. Even when signals for pedestrians exist, there may not be enough time to safely cross the street, a serious limitation for those with limited mobility. In many cases, the built environment can actually discourage—even prevent—physical activity.

The built environment includes indoor spaces, too. If the building you work in has clean, safe, and accessible stairs, you will be more likely to use the stairs rather than the elevator. Even the design of offices and workspaces can influence activity. If your office has a desk and a chair, it is almost guaranteed you will sit much of the day. Even the small increase in activity that comes from using a standing desk or an alternative to a traditional chair, like sitting on a stability ball, can add up during the day. Some people even have treadmill desks, so they can walk while they work!

At work and at home, technology and labor-saving devices make it easy to be inactive. At work you can communicate with coworkers by phone or email instead of walking to their office to talk. Entire groups of people can have meetings via video in which each person is seated at their own desk, even though everyone works in the same building. At home you can change the TV channel, connect with friends and family, even order dinner from the comfort of your couch. Riding lawn mowers and leaf blowers reduce the physical effort needed to do yard work and robotic vacuums allow you to sit and watch your floors get cleaned.

The good news is that you can change the way in which you interact with the toxic activity environment to increase your level of activity. You may need to drive to a store or restaurant if it is too far to walk, but you can park farther away to get a few extra steps. You can get up from your desk to talk to a coworker rather than calling or sending an email. At home you can get up off the couch during commercials or take short “screen time” breaks to move. And it is perfectly alright to leave the leaf blower in the garage and use a rake to clean up the yard.

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Your metabolism (and how to speed it up)

Posted on November 17, 2014 | 2 comments

Many people are interested in speeding up their metabolism in an effort to lose weight. There are drugs, supplements, and even certain foods that are thought to increase metabolism. The effectiveness of many of these things is unproven and some may actually be dangerous. The goal of this article is to explain what the term “metabolism” really means and how it can be changed.

Metabolism refers all of your body’s processes that expend energy, or burn calories. Practically, this is how much carbohydrate, fat, and protein is burned throughout the day to provide energy for your cells. If you expend more energy than you consume in your diet, you will lose weight.

The amount of energy you expend in a day is composed of three main components: your resting metabolic rate (RMR), something called the thermic effect of food (TEF), and the energy you expend in activity.

Resting metabolic rate (RMR) is sometimes called the basal metabolic rate (BMR), but many people refer to it as their “metabolism.” No matter which name is used, it refers to the calories you burn at rest. It represents the energy needed to maintain your essential body functions: heart rate, breathing, body temperature, and normal cellular processes.

The RMR is important because it represents about 60–70% of the total calories a typical person burns in a typical day. Even though RMR is important, you shouldn’t worry about it too much.

First, it is difficult to change. RMR is based mostly on your lean body mass, so the only way to increase it is to gain muscle mass. While this is a good goal, it is challenging to do, especially while you trying to losing weight.

Second, although it does vary among people, it isn’t as different as people like to think. It is easy to think that someone who gains weight has a “slow metabolism” or that someone who is thin must have a “fast metabolism.” In reality, the RMR probably isn’t much different, certainly when you take lean body mass into account. The explanation for the differences in weight among people probably has more to do with what they eat and how active they are.

The thermic effect of food (TEF) represents the energy needed to digest, absorb, and store the nutrients you eat. It accounts for only about 10% of your total energy expenditure and it is practically impossible to change, so you can ignore it.

Activity is the most variable component of energy expenditure and the one you can most readily change. Obviously, it will vary based on how active you are, but for most people it accounts for 20–30% of total energy expenditure.

Activity includes both purposeful movement such as exercise and doing work or tasks that require you to move. Activity also includes non-exercise activity thermogenesis or NEAT, the calories you burn when you move around, but not in a purposeful way. Maintaining your posture when sitting or standing, fidgeting in your chair, or other light movements count as NEAT.

The surest way for you to increase your metabolism is to limit the time you spend sitting, be active as possible at all times, and dedicate time to exercise every day. Doing prolonged aerobic exercise such as walking, jogging, or exercise classes directly burns calories and including strength training will help increase your muscle mass, which can increase up your RMR.

The bottom line is that speeding up your metabolism requires you to move. So, get up off the couch and go for a walk!

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Funny calorie math.

Posted on November 17, 2014 | Leave a comment

Have you ever heard that a few extra calories each day—an extra soda, for example—can add up to significant weight gain over time? Or that making small changes in what you eat, such as skipping dessert, can promote weight loss? If so, you are familiar with the concept of energy balance. And if you were ever surprised by those claims, you are familiar with what I call funny calorie math.

This is the topic of my Health & Fitness column in the Aiken Standard this week.

Your body weight at any time is determined by the balance between the energy you take in and the energy you expend. The “energy in” part is simple, it’s the calories in the food you eat.

Your energy expenditure is determined by your basal metabolic rate (BMR), the calories burned keeping you warm and alive, as well as the energy you expend in activity. Of these, the BMR accounts for the majority of your energy expenditure, but you have the most control over your level of activity.

According to this energy balance model, eating or drinking an additional 250 calories per day would add up to about one pound of weight gain every two weeks and 26 pounds after one year (using the rough estimate that to gain a pound requires 3500 extra calories.

+250 calories/day  x  7 days/week  =  1750 calories/week  =  3500 calories/2 weeks

3500 calories/2 weeks  x  1 lb. weight gain/3500 calories  =  1 lb. weight gain every two weeks  =  26 lbs. weight gain per year!

Calculations like this are common, typically used to point out how fattening a particular food or beverage can be. But the same principle can be applied in reverse to determine weight loss.

Example: Eat (or drink) and extra 250 calories per day

250 calories/day  x  7 days/week  =  1750 calories/week  =  3500 calories/2 weeks

3500 calories/2 weeks  x  1 lb. weight loss/3500 calories  =  1 lb. weight loss every two weeks  =  26 lbs. weight loss per year!

The same formula predicts that cutting back by 250 calories per day should lead to losing 26 pounds in one year. This idea is the basis for suggesting that making small changes to your diet can lead to significant weight loss over time.

You can do the same thing with physical activity, too. Adding a 45-minute walk, which burns approximately 250 calories, each day should lead to the same 26 pounds of weight loss in a year.

Example: walk 2.5 miles in 45 minutes each day, using the rough estimate that you will burn 100 calories per mile.

2.5 miles/day  x  100 calories/mile  =  250 calories/day

250 calories/day  x  7 days/week  =  1750 calories/week  =  3500 calories/2 weeks

3500 calories/2 weeks  x  1 lb. weight loss/3500 calories  =  1 lb. weight loss every two weeks  =  26 lbs. weight loss per year!

The assumption, of course, is that you aren’t changing anything else as you eat 250 fewer calories or burn an additional 250 calories per day through exercise. It would be relatively easy to offset the energy expended though a walk by even a small change in what you eat. This is the biggest weakness of this energy balance model—in order for it to accurately predict weight loss or gain, nothing else can change.

Unfortunately, this isn’t the way it really works. Changes in body weight through eating or exercise also lead to changes in total energy expenditure. As you lose weight, the total calories you burn in a day drops, mostly due to a decrease in BMR, since it is based on your body weight. The result is that over time you don’t lose weight as quickly. The exact opposite occurs with weight gain, which causes BMR to go up, limiting weight gain.

This leads to a different outcome: the extra 250 calories per day is likely to lead to a weight gain of closer to 10 pounds (maybe less) due to your BMR increasing as you gain weight over the year. And the estimation of weight loss will be different, too, given that BMR will drop slightly over time.

This is one of many reasons why exercise is important for weight loss. You can offset the lower BMR that occurs as you lose weight by increasing energy expenditure through activity. Additionally, regular exercise can add to the weight you lose through a diet and help keep the weight off later.

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