Say what? A health and fitness vocabulary lesson.

When I write about health I routinely use terms like exercise, activity, and fitness. I often get asked why I use these different words since they all have a similar meaning. That is an excellent question, since these terms are related they have different applications for health and wellness. This is the topic of my Health & Fitness column in the Aiken Standard this week.

vocabulary crossword


Physical activity (PA) is defined as any movement produced by muscles that expends energy. Physical activity can be classified as occupational, what you do at work, and leisure-time, what you do in your free time. Occupational PA can vary greatly depending on the job, but it is low for most of us who spend much of our work day sitting. Leisure-time PA is all activity outside of work. This is of great interest to researchers since it reflects how we chose to spend our discretionary time. Physical activity can be measured by questionnaires or using devices such as pedometers, which count the steps you take, or motion sensors, which measure how much you move.

Exercise is a type of physical activity that involves planned, structured, and repetitive movement to improve or maintain physical fitness. Physical fitness, then, is a set of attributes that relate to the ability to perform physical activity and exercise. The components of physical fitness include endurance, strength, and flexibility. Basically, participation in physical activity and exercise improves your fitness and the greater your fitness, the better able you are to participate in physical activity. This is true for completing occupational tasks as well as traditional exercise, such as jogging or lifting weights.

The good news is that both physical activity and exercise have health and fitness benefits. Physical activity can vary in intensity, from light (slow walking), moderate (brisk walking), or vigorous (exercise like running). The 2018 U.S. Physical Activity Guidelines recommend that, at a minimum, all adults participate in moderate-intensity physical activity for 2 hours and 30 minutes per week or vigorous activity for 1 hour and 15 minutes per week along with strengthening exercises at least 2 days per week. You can meet this recommendation by going for a brisk walk for 30 minutes on 5 days per week or running for 25 minutes on 2 days per week or some combination of the two. Additional benefits come from doing more, either higher intensity or longer duration activity.

Vigorous exercise is the best way to improve fitness while moderate-intensity activity is strongly linked to health benefits. Fitness benefits result from adaptations in the heart and muscles, which get stronger and become better able to resist fatigue. These changes also lead to health benefits including lower blood pressure, cholesterol, and glucose as well as helping with weight loss and weight control.

Research suggests that health and fitness benefits also result from light-intensity or intermittent activity, especially if it replaces sitting. At home or at work, the more time you spend sitting, the poorer your health, even if you exercise every day. One study shows that getting off the couch and stepping in place during TV commercials results in nearly 25 minutes of activity per hour and burns about 150 calories, compared to 80 calories just sitting the entire time. You won’t get in great shape doing this, but it will increase your overall activity.

With this is mind, a good recommendation is to reduce sitting time in favor of light activity—stand while you read the paper or walk around while you talk on the phone—and participate in moderate or vigorous activity each day by going for a brisk walk or doing other exercises, including strength training.


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Active transportation is a WIN, WIN, WIN

Since Earth Day was last week, this is a good time to be mindful of the influence we have on our environment and what we can do to reduce that impact. The good news is there are that there are things we can do that are good for our health and the health of our planet. Active transportation, which includes walking, cycling, and other physically active modes of moving from place to place, is one example.

Active transportation has important environmental, health, and economic benefits for individuals and communities. Promoting active modes of transportation can reduce pollution, increase physical activity, and benefit both people and communities economically. In some areas, active transportation can replace motor vehicle use entirely. More commonly, though, physical activity can be combined with cars or public transportation to replace parts of trips.

Significant and accumulating evidence shows that motor vehicle use is a primary cause of air pollution. This includes greenhouse gasses like carbon dioxide and pollutants such as nitrogen dioxide, ozone, and particulate matter that are released by combustion engines and industry. This has been linked to climate change and health problems, including pulmonary and cardiovascular diseases, contributing to 200,000 deaths per year.

The transportation sector is the largest greenhouse gas emitter in the United States, so physically active modes of transportation that replace motor vehicle use could have a significant impact on air pollution and health. Estimates suggest that even a small decrease in vehicle miles traveled, a measure of motor vehicle use, by increasing active transportation could lead to reductions in particulate matter and greenhouse gas production.

In addition to environmental benefits, increasing active transportation has clear health benefits. As you might expect, spending more time commuting in a car is associated with an increased risk of obesity and more active commuting is associated with a lower risk of obesity. Beyond the influence on body weight, people who use physically active modes of transportation have a lower risk of diabetes and hypertension as well as death from cardiovascular diseases.

People who engage in active transportation get an average of 12–15 minutes of physical activity per day and 30% meet the 30 minutes per day recommendation. Considering that over a quarter of trips are less than 1 mile and most are less than five miles, most people could replace at least some driving with walking or cycling.

The cost of implementing active transportation is often cited as a reason not to, but individuals and communities can benefit economically from increased active transportation. Transportation represents the second largest expense for American families and may have a greater impact on low-income households. Given that active transportation is almost always more affordable than using a car, this could help many people and families make ends meet. 

Communities that develop infrastructure and policies to promote active transportation experience direct and indirect benefits. These benefits include increased residential and commercial property values as well as the fact that people who are walking or cycling are more likely to visit businesses along their route. Depending on the location and nature of the project, implementing active transportation can have a positive cost-benefit ratio and promote job creation.

Given the environmental, health, and economic benefits, active transportation is a win, win, win for our community. Across the country, cities large and small are implementing infrastructure and policies to make them safer and more convenient for pedestrians and cyclists. Since everyone benefits from a community that supports active transportation for work and leisure, we should take steps in that direction.

Exercise during allergy season

Springtime has arrived in our area, which means warmer weather, blooming flowers, green grass, and, for many, seasonal allergies. If you suffer from seasonal allergies, you may want to know if it is safe to exercise outdoors. The short answer is yes, provided you take the right precautions. This is the topic of my Health & Fitness column in the Aiken Standard this week.

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Don’t be an April Fool when it comes to weight loss claims.

Diets don’t work!

Exercise can actually make you gain weight!

You can take supplements that will melt fat away while you sleep!

Claims like these should make you wonder if someone is trying to fool you. Since April Fools’ Day just past, it is worth learning the truth about these common weight loss myths.

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Diets don’t work

Considering that most people who lose weight end up gaining it back, this belief is understandable. The fact is that diets do work—that is how people lost weight in the first place! The problem is that many diets simply aren’t sustainable and don’t teach healthy eating habits necessary to keep the weight off. The result is that after the diet ends, a return to old eating patterns leads to gaining the weight back. The solution, of course, is to find a diet that you can stick with even after you have lost weight, one that teaches you how to make healthy choices and adapt your lifestyle.

Exercise doesn’t lead to weight loss

The traditional advice for losing weight is to eat less and exercise more. But some research suggests that exercise itself doesn’t lead to significant weight loss. In fact, exercise alone results in lower weight loss compared to diet only or diet plus exercise. While this is true, concluding that exercise isn’t important is a mistake.

First, even if exercise only leads to a small amount of weight loss (about a half pound per week in my research) it does add up over time and can help someone achieve their weight loss goal more quickly. Second, research involving individuals who have succeeded at long-term weight loss in the National Weight Control Registry shows that exercise is important. It is noteworthy that 94% of these “successful losers” increased their physical activity in order to lose weight and 90% said that they maintain their weight by exercising an average of 60 minutes every day.

You can boost your metabolism and burn fat using supplements

Losing weight really does require making changes to your eating and exercise behaviors. Many of these changes can be difficult, so it is no surprise that people look for shortcuts. And there is no shortcut more appealing than a supplement that will increase your metabolism and burn fat while you sleep.

Keep in mind that there are no dietary supplements that have been shown to be safe and effective for promoting long-term weight loss, despite what the manufacturers claim. In fact, some could even be dangerous. The only way to make a meaningful change in your metabolism is to exercise and significant weight loss simply won’t happen unless you change your diet.

Be especially skeptical when you see words like “flush” and “cleanse,” which are meaningless and have nothing to do with weight loss. There are a few prescription medications and one over-the-counter drug (Orlistat) that has been shown to promote weight loss—but only when combined with a healthy diet and exercise.

Hopefully this advice will help you make healthy decisions and avoid becoming an “April Fool” when it comes to weight loss claims. The good news is that you can start losing weight today by making some simple changes including reducing your portion sizes at meals, choosing water or other calorie-free beverages when you are thirsty, and making it a point to be active every day. These modifications can lead to weight loss now and are exactly the type of changes you need to make to keep the weight off in the long run.

 

Sickeningly sweet: Added sugar and your health

You are probably aware that eating too much sugar is bad for your health. Excessive sugar intake causes hormonal changes and inflammation that can lead to obesity, diabetes, heart disease, and cancer. For decades an emphasis was placed on lowering fat intake, especially saturated fat and cholesterol, to reduce the risk of obesity and heart disease.

Unfortunately, much of this advice was misguided and while fat intake went down, sugar consumption in processed and prepared food increased. This is now seen as a primary cause of the current obesity and diabetes epidemic. The impact of sugar on health and steps you can take to reduce sugar intake are the topic of my Health & Fitness column in the Aiken Standard this week.

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Let’s Agree to Agree About Food

Eating a healthy diet is a goal for many people to help them treat or prevent disease, improve exercise performance, or maintain a healthy body weight. If you pay attention to news about food and nutrition you have probably noticed that there is a great deal of controversy about what constitutes a healthy diet. It’s easy to find lists of foods to avoid and things to eat every day. Unfortunately, lists from different sources may not be the same or, worse, a food that is on one “never eat” list is on another “always eat” list.

There is a different approach you could take to plan the foundation for a truly health way to eat. Instead of focusing on what is different, think about what recommendations are shared among most “healthy” diets. Here is some diet advice that almost everyone agrees on. This is the topic of my Health & Fitness column in the Aiken Standard this week.

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Chill out! Understanding and managing stress.

There is no doubt that the past year has been especially stressful. From very real health and economic concerns to social distancing and working or learning from home, most of us are experiencing a higher level of stress. Much of this is unavoidable but finding ways to reduce the impact stress has on is essential for maintaining our physical and mental health. This is the topic of my Health & Fitness column in the Aiken Standard this week.

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What you need to know about muscle cramps during exercise

Muscle cramps are a common condition experienced during endurance exercise and many sports. Known as exercise-associated muscle cramps (EAMC), these sustained and painful muscle contractions tend to occur during prolonged exertion including exercise and physical labor that results in fatigue. Despite their frequency, the cause and treatment for muscle cramps is not well understood by many recreational and competitive athletes.

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Muscle cramps that occur during exercise are widely thought to be caused by dehydration and electrolyte imbalances in the muscle. This makes sense, as muscle cramps seem to be more likely during prolonged exercise in a hot, humid environment in which sweat loss could cause a loss of both water and salt from sweat. Sometimes, EAMC are erroneously referred to as “heat cramps,” even though they can occur in cooler conditions. Furthermore, dehydration and electrolyte imbalances would affect the entire body, whereas muscle cramps occur only in the working muscles, typically the gastrocnemius in the lower leg. It is also worth noting that the most effective treatment for muscle cramps—stretching the affected muscle—does not replace fluid or electrolytes. These observations suggest that EAMC have a cause other than fluid and electrolyte loss during exercise.

 Research also does not support the notion that dehydration or electrolyte abnormalities are the cause of muscle cramps that occur during exercise. For example, in one study of competitors in an Ironman triathlon, there were no significant differences between those who experienced muscle cramps and those who did not in blood electrolyte concentrations or body weight changes (an indicator of dehydration). The development of EAMC was related to faster race times and a history of cramping. Other studies in a laboratory setting show that muscle cramps still occur even when electrolyte balance and fluid replacement is maintained. These findings and other research led to the development of an alternate theory of the cause of muscle cramps during exercise.

Understanding the cause of EAMC requires a brief primer in muscle physiology. Muscle contraction occurs when nerves, from the spinal cord, called motor neurons, stimulate the muscles to shorten and produce force. The force production by the muscle is controlled by a host of receptors that either stimulate or inhibit the muscle. One of these, the muscle spindle, responds to stretch and causes muscle excitation. Another, the Golgi tendon organ (GTO), inhibits muscle activation and causes relaxation. Working together, the muscle spindle and GTO regulate force production during exercise.

Just as repeated muscle contraction over time can lead to muscle fatigue, the pattern of the motor neurons stimulating the muscle can also be altered during prolonged, intense exercise. This causes an excessive stimulation of the muscle spindle and decreased activation of the GTO, resulting in uncontrolled muscle contraction—a cramp. This also explains why stretching is an effective treatment for muscle cramps. By engaging the GTO, the muscle relaxes and the cramp is eventually relieved.

The prevention of muscle cramps is obviously of great interest, especially for athletes who are prone to develop them. Given that muscle fatigue is a condition underlying most cramps, adequate training and conditioning to increase endurance is important. There are a number of popular preventive strategies, including increasing fluid and electrolyte intake, consuming specific foods and beverages like pickle juice and bananas prior to exercise, and taking substances like quinine. However, experimental evidence for these strategies to reduce EAMC is lacking and their effectiveness is based mostly on anecdotal reports.

For now, the best way to prevent muscle cramps is to prepare yourself through training and nutrition for both the environmental conditions and exercise itself. And if you get a muscle cramp during exercise, immediate stretching is the best way to relieve it.

Should you eat like a caveman? What you need to know about paleo and keto diets.

Which diet is the best? This is one of the most common questions about nutrition and health, with implications for weight control, chronic disease prevention and treatment, and exercise performance. Unfortunately, this is no simple answer to this question. While there are certain eating patterns and aspects of specific diets that are considered to be beneficial, there is no single diet that has been shown to be the “best.”

As a general rule, healthy eating should be informed by nutrition science, not determined by the latest trends. Many fad diets raise concerns because they restrict or over-emphasize certain foods or nutrients, rely on meal replacements or supplements instead of real food, or are supported by limited evidence.

The Paleo and ketogenic (Atkins) diets are examples of popular diets that are at odds with traditional nutrition recommendations, going against the poor “low-fat” advice we have long been provided. Given the popularity of these low-carbohydrate diets, it is worth exploring the benefits and drawbacks of each to help you decide which is right for you.

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Exercise and the gut microbiome

We tend to think of bacteria as something to avoid. Germophobes beware, but our bodies are literally covered and filled with bacteria. From our skin to the lining of our GI tract, bacteria are literally part of us. For sure, some bacteria are harmful, but many more play an important role in our health. The balance between the helpful and harmful bacteria seems to be important for health; diseases from eczema to irritable bowel syndrome can result from an imbalance.  

The combination of bacteria in our bodies is known as the microbiota, the genes of which are called the microbiome. Researchers study the bacteria themselves (microbiota) and the genes (microbiome) and use both as an indicator of the balance between “good” and “bad” bacteria. This is especially relevant in the large intestine, where there has been much research into the role of gut bacteria on health.

Gut bacteria

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