Category Archives: Health & Fitness

Get fit (and stay cool) in the pool

It’s hot! Whether you are swimming laps or splashing in a lake, swimming is a great way to stay cool. Swimming is also an excellent exercise to get in shape, build muscle, and to help you lose (and maintain) weight. Lap swimming is about as aerobically demanding and burns as many calories as land-based exercise such as walking or jogging. The benefits of swimming is the topic of my Health & Fitness column in the Aiken Standard this week.

Swimmer


There is nothing that feels better on a hot summer day than going for a swim. But beyond being a fun way to cool down, swimming is a great way to get in shape. Swimming is also an excellent exercise for injury rehabilitation or for people with conditions like arthritis.

The fitness benefits of swimming are well established. Since swimming is a whole-body exercise it uses all of your major muscle groups, building strength, endurance, and aerobic fitness. Highly trained swimmers have VO2max values, considered the best measure of aerobic fitness, that are similar to runners and cyclists. If you have doubts about the fitness benefits of swimming, think about how muscular and lean Olympic swimmers are.

Depending on the stroke and speed, swimming ranges between 5 to 10 METs. (METs are units used to measure the intensity of activity; one MET is equivalent to sitting at rest) For example, doing the backstroke at a moderate speed is about 5 METs while swimming laps freestyle with vigorous effort is about 10 METs.

This range is similar to walking at 4 mph up to jogging at a 9 minute per mile pace. What if you are just spending time in the pool or lake rather than swimming laps? Swimming leisurely is 6 METs, still a decent workout.

Swimming is a great way to burn calories, too. Even at a moderate pace, swimming laps for 30 minutes can burn over 200 calories. The exact energy expenditure depends on the stroke (butterfly is highest, backstroke is lowest) and the speed, but for most people swimming will burn as many calories as spending the same amount of time exercising on land.

There are two major reasons for this. First, water is more dense than air, so you need to expend more energy to move your body through the water. Second, swimming is a whole-body exercise which requires more muscle activity compared to walking or jogging which mostly involve the legs.

You may be surprised to learn that novice swimmers expend more energy per lap than elite swimmers. For example, one study showed that competitive swimmers expend only 280 calories to swim a mile, while less experienced swimmers burn about 440 calories to cover the same distance. The reason for this is that experienced swimmers are more efficient, so they expend less energy.

Aquatic exercise is popular for both therapeutic and fitness purposes, especially for people who don’t tolerate exercise on land well. When you are submerged up to your waist, 50% of your weight is supported; when you are up to your chest, about 75% is supported. This reduces the impact of exercise in the water, perfect for people who have arthritis, osteoporosis, fibromyalgia, severe obesity, or who are recovering from injuries.

Exercise in the water doesn’t have to mean swimming laps. Water aerobics, aqua walking or jogging, and resistance training using foam “weights” or webbed gloves offer safe ways to increase strength and endurance for almost everyone. Most fitness facilities that have a pool offer group aquatic exercise classes and you can find instructions online for exercises that you can do in your own pool. If you are interested in using the pool for exercise, you can find information about aquatic exercise in general here and links to suggested exercises here.

The hot summer weather makes swimming and other water exercise appealing. But even if you don’t use the time for exercise, spending time playing in the pool or lake can still burn as many calories as going for a walk and is a great way to have fun and cool down!


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Get fit in just minutes per day!

We are cautioned to be skeptical of claims that you can lose weight while eating everything you want or that you can get in shape without spending hours at the gym. For good reason, too. These claims are essentially the equivalent of a get rich quick scheme, with the same expected results.

But there are some popular exercise programs that aim to increase your endurance, build muscle, and improve your health in less than 10 minutes per day. One is a popular seven minute workout that was published in a fitness journal and received much media attention. There is even an app for your phone that will guide you through the workout. If seven minutes seems like too much, there is even a four minute version! But is less than 10 minutes of exercise per day enough? This is the topic of my Health & Fitness column in the Aiken Standard this week.

Stopwatch


Current guidelines call for all adults to 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. You can meet this recommendation by going for a brisk walk for 30 minutes on 5 days each week, running for 25 minutes on 3 days per week, or some combination of the two. In addition, you should do strengthening and flexibility exercise at least two days of the week.

For many people, these recommendations seem daunting. In order to make it easier to meet these goals, the exercise time can be divided into shorter sessions. For example, three 10 minute walks are a substitute for walking 30 minutes at once. But some people may still find doing enough exercise to get in shape a challenge, which is why the seven minute exercise program became so popular. And for many, an effective way to improve their fitness.

The effect of exercise on health and fitness is determined by the dose—the combination of intensity and duration. Improvements in aerobic fitness and strength are more related to the intensity of the exercise. As little as a few minutes per day of high-intensity training can be enough to improve fitness, which is why these programs include a combination of vigorous aerobic and strength exercises. In fact, bouts as short as one minute of very intense exercise can improve strength and aerobic fitness better than lower intensity exercise done for a longer time.

Because these programs tend to be intense means that you have to be fit to even get started. A very short program may not be a good choice for people who are not already in shape or who are new to exercise. There may be a greater risk of injury in people who are unfit and start exercising at a high intensity. At the very least, muscle soreness is likely and may impact your ability—and motivation—to repeat that exercise the next day. It is smart to start slowly and gradually increase exercise duration and intensity as your fitness improves.

If you are interested in starting a 10 minute per day routine you may want to start with an app or video that leads you through daily workouts. These may involve using your own body weight for resistance or may require using minimal equipment like dumbbells or resistance bands. If you are more of an expert, you could create your own routine using exercises you are familiar with. You should also warm up before and cool down after each session, something that may not be included in the 10 minute program.

While a 10 minute exercise program can improve your fitness, it shouldn’t be the only physical activity you get. Optimal health and fitness benefits are realized by combining daily physical activity with regular exercise. The best advice is to be as active as possible every day by limiting the time you spend sitting and looking for opportunities to move. Walking instead of driving, using the stairs, and taking the dog for a walk are good ways to increase your activity. You should also dedicate time for exercise to improve your strength and aerobic fitness at least 2–3 days per week. A very short exercise routine may make it easier for you to meet this goal.


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FITT-SPF: How to exercise safely in the sun this summer.

People who exercise are probably familiar with FITT—frequency, intensity, time, and type—the basic principle behind almost all fitness programs. The FITT principle applies to everything from running to weightlifting to yoga. For people who exercise outdoors there are three more letters that are important to know, especially in the summer: SPF. This is the topic of my Health & Fitness column in the Aiken Standard this week.

woman running on beach


First, a bit more about FITT. Exercise prescriptions are based on four key concepts that allow training to be tailored to meet individual goals. Frequency refers to how often you are training, usually expressed as days per week. Intensity is how hard you are working, which could be running or walking speed or the amount of weight you are lifting. Time is simply how long you are exercising per session. Type is the specific type of training you are doing, which we typically think of as endurance (like walking), resistance (lifting weights), or flexibility (stretching).

Keep in mind that there is interaction between these components. Less intense exercise like walking is typically done for longer than more intense exercise such as interval training can be done in shorter sessions. Some people focus on one type of training at a time, as in weight lifting to increase strength or yoga to enhance flexibility, while others do exercise that includes some endurance, resistance, and flexibility training in the same session. Many group exercise classes and programs like CrossFit are examples of combining multiple aspects of fitness in one session. Since everyone has a different starting fitness level and goals, FITT can be manipulated to meet a variety of needs.

Many types of exercise, especially endurance or aerobic training, can easily be done outdoors. Walking, running, cycling, and water sports like stand-up paddle boarding and kayaking, are popular outdoor activities, especially in the summer. Being active outdoors in nature improves health and wellbeing beyond the fitness benefits of the exercise itself, so “going green” with your workouts is a great idea! Some sun exposure is necessary for your body to produce vitamin D, an essential nutrient. But excessive sun exposure can increase the risk of skin cancer, the most commonly diagnosed form of cancer.

Excessive sun exposure is a real risk of exercising outdoors, especially for prolonged periods of time. Cycling, running, water sports, and skiing have been identified as sports that increase the risk of some types of skin cancer. Unfortunately, sunscreen use among outdoor athletes is low. According to survey results, at least half of college athletes never apply sunscreen before games and practices and those who report using sunscreen don’t use it regularly.

Marathoners, who can accumulate 1,000 or more hours of sun exposure during training per year, are more likely to be diagnosed with skin cancer than non-runners, but only about half use sunscreen, according to one study. Regular sunscreen use is even lower in the general population—about 30% of women and 15% of men—so even if you aren’t an athlete it is likely you are still at risk.

The good news is that there is much you can do to reduce your risk of skin cancer while you are active outdoors. First and foremost, properly applying (and reapplying every two hours) a broad-spectrum sunscreen with an SPF of 30 or higher is the best way to protect exposed skin. Some sunscreens are more water and sweat resistant, but still need to be reapplied regularly.

Second, covering exposed skin with light-colored clothing, a hat, and sunglasses is smart. Some clothing is more resistant to UV rays than others, so look for a higher ultraviolet protection factor (UPF). Obviously, you need to find a balance between protecting your skin and allowing sweat and heat loss to keep you cool.

Third, try to exercise outdoors in the early in the morning or later in the day when the sun’s rays are less direct. Keep in mind that you should still use sunscreen on cloudy days as UV rays can penetrate clouds. This also tends to be when temperatures are lower, too, so exercise may be more comfortable.

The bottom line is that summer is a great time to be active outdoors. By taking a few precautions you can do it safely, especially when it comes to reducing your risk of skin cancer from excessive sun exposure. You can learn more about skin cancer risk and prevention from the American Cancer Society and the American Academy of Dermatology.


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Sports physiology in the Tour de France

 

This week marks the start of the 2017 Tour de France. This year the race covers 2200 miles in 21 days of racing, comprised of team and individual time trials as well as stages through cities, countryside, and mountains of France. The Tour de France is interesting to me because it provides an excellent opportunity for a short lesson in sports physiology. Which I did in my Health & Fitness column in the Aiken Standard this week.

Tour de France


All the riders in the Tour are exceptionally fit since their bodies have adapted to years of dedicated, intense training. Endurance sports like cycling are dependent on the delivery of oxygenated blood to the muscle to produce ATP, the energy needed to sustain exercise. The riders have large, strong hearts, resulting in the ejection of more blood to the muscle. Within the muscle there is an increase in the number of capillaries, the small blood vessels that deliver blood to the muscle, and mitochondria, the part of the cell that produces most of the ATP. Together, these adaptations allow the muscle to produce more ATP without fatigue, allowing the athlete to exercise at a higher intensity for a longer time.

But training isn’t the only reason these athletes can sustain such intense exercise for so long. Proper nutrition, especially what the athletes eat and drink before, during, and after each stage, also plays an important role. Intense endurance exercise like cycling relies on carbohydrates, in particular, muscle glycogen, as a fuel. Muscle glycogen is a storage form of glucose, sugar that the muscle converts into energy. During prolonged exercise that lasts several hours, muscle glycogen levels can be severely depleted.

Eating carbohydrates before exercise can boost muscle glycogen levels, so cyclists eat carbohydrate-rich foods for breakfast before each stage. They also consume carbohydrates in the form of sports drinks (think Gatorade) and energy bars prior to starting. In fact, they start replenishing their muscle glycogen immediately after finishing the previous day’s ride. This usually begins with a recovery beverage, which may contain some protein for more rapid muscle glycogen synthesis, and extends through carbohydrate-rich meals and snacks that afternoon and evening.

During exercise it is crucial to maintain adequate blood glucose levels, which tend to drop since the muscle is using so much as a fuel. Failure to replenish blood glucose results in what cyclists call “hitting the wall” or “bonking,” which is like your car running out of gas. To prevent this, glucose must be replenished, typically with sports drinks, energy bars, or a sugary mixture called goo.

Prolonged, intense exercise, especially in the heat, results in a high sweat rate which can lead to dehydration. Sweat loss of several liters per hour is not uncommon during cycling, so fluid intake is essential. This means that cyclists spend a lot of time drinking water while they ride. Sports drinks are also commonly used since they contain carbohydrates and electrolytes in addition to water.

Endurance events like cycling, especially multi-stage events like the Tour de France, highlight important concepts of sports physiology. Even though you may never compete at that level, understanding how training can improve your endurance is relevant if you cycle—or run, walk, or swim—for exercise. Knowing how proper nutrition before, during, and after exercise can improve performance can help you make better decision about what to eat. Hopefully, it also gives you a greater appreciation for the science that goes into a performance like the Tour de France.


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From Worse to Bad: Moving in the right direction even if your health habits aren’t perfect

Recently, someone told me that her sister was quitting smoking by switching to e-cigarettes. “Isn’t that bad?” she asked. I told her that, sure, smoking e-cigarettes was bad but that smoking tobacco cigarettes was worse, so she was making a positive (and hopefully temporary) change. The benefits of making changes to health habits, even if they aren’t perfect, is the topic of my Health & Fitness column in the Aiken Standard this week.

cigarette vs e-cig

It is no secret that smoking has serious negative health effects. Cigarette smoking more than doubles the risk of heart disease and stroke, is by far the leading cause of lung cancer and other lung diseases, and is responsible for nearly 500,000 deaths per year. If you smoke, quitting now is probably the most important step you can take to improve your health.

But quitting smoking is difficult. Obviously, there is the addictive nature of nicotine that makes smoking cessation challenging. Beyond the drug effect, smoking also has a behavioral component. This includes what a smoker does first thing in the morning, after a meal, or on a work break as well as the act of holding a cigarette in his or her hand. Add to that the social aspects of smoking, including the influence of friends and family members, and it is easy to understand why it is a difficult habit to break.

Nicotine replacement therapy in the form of gum, lozenges, and patches as well as prescription medications can help with withdrawal symptoms. Nowadays, many smokers are turning to electronic cigarettes (e-cigarettes) to help them quit. The research on the effectiveness of using e-cigarettes to quit smoking is mixed, with some studies showing a benefit, some showing no real effect, and others suggesting that e-cigarettes actually lower the quit rate.

Parts of an e-cigarette

Even though most smoking restrictions also apply to e-cigarettes, this form of smoking seems to be more socially acceptable than tobacco cigarettes. This is largely due to the fact that e-cigarettes are thought to be less dangerous to the smoker and to people around the smoker. While there isn’t much conclusive evidence on the health effects of e-cigarettes, a conservative interpretation is that e-cigarettes are better than smoking tobacco cigarettes but worse than not smoking at all.

So, switching from smoking cigarettes to e-cigarettes is making a move in the right direction, from worse to bad. And if using e-cigarettes helps a smoker start the quitting process it is probably a good idea. Obviously, not smoking at all is the goal, but this may not be reasonable for everyone, especially in the beginning. When it comes to improving your health, doing something is better than doing nothing, even if it isn’t perfect.

This obsession with being perfect extends beyond smoking cessation. There is a perception that if the diet or exercise program aren’t the “best,” they won’t be effective. So, many people struggle to find the perfect diet before trying to lose weight or wait to identify the best workout before starting an exercise program. This can lead people who need to become more active or change the way they eat to delay starting the process. And it is almost always a long process.

There are very few people who can change difficult habits quickly and easily. Even the people who make it look easy will tell you that developing a healthy lifestyle is a series of steps and missteps and that positive changes accumulate over time. The lesson is that getting started on improving your health now is more important than achieving the perfect outcome right away.  Just like switching from tobacco cigarettes to e-cigarettes isn’t the ultimate goal, making positive changes to your diet and exercise habits can have benefits now and give you a foundation from which to make more significant changes later.

For example, drinking water instead of sweet tea or soda when you eat lunch at a fast food restaurant is a good start. Obviously, the goal would be not to eat fast food meals, but modifying those meals will cut out some unhealthy choices. Similarly, going for a 10 minute walk after dinner instead of watching television is a step (literally!) toward a goal of less sedentary time longer exercise sessions. Neither are perfect, but you should recognize both as positive changes that move you away from behaviors that are worse.


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School gets out, weight goes up: Why summer time is the right time to worry about childhood obesity.

Obesity is a major concern for adults, linked to several leading causes of death and numerous other health problems. What you may not know is that obesity is also a serious health issue for children. It is troubling to note that nearly one-third of school-aged children and teenagers are over a healthy body weight and nearly 20% are considered obese. Remarkably, 10% of infants, toddlers, and preschoolers, are also considered obese.

This is important because the common combination of poor nutrition, physical inactivity, and obesity has physical, psychological, and social consequences for children that frequently persist into adulthood. There are many reasons why childhood obesity occurs and much that can be done to prevent it. Now that school is almost out for the summer, this is a critical time of year to focus on good nutrition and activity to help prevent unhealthy weight gain in kids. This is the topic of my Health & Fitness column in the Aiken Standard this week.

kids-jumping


Overweight and obese children are at increased risk for type 2 diabetes, high blood pressure, heart disease and even stroke – conditions usually associated with adulthood. Even if an overweight child does not have these conditions now, he or she is likely on that path. Many experts predict that children born today will be the first generation in history to have a shorter lifespan than their parents due to obesity-related diseases that begin in childhood.

Children who are overweight are also more likely to suffer other consequences including lower self-esteem, social functioning, and academic performance. Overweight children are also less likely to play sports or participate in other forms of physical activity. Considering that the consequences of obesity are made worse by low levels of activity, this creates a cycle leading to poorer and poorer health.

There are numerous potential causes of obesity in children, but the most likely suspects are too little activity and excessive calorie intake, largely because of added sugars. Fewer than half of all kids meet the minimum recommendation of 60 minutes of activity each day and many children spend as much time watching television or playing video games as they do in school. We shouldn’t be surprised that we have a childhood obesity problem!

While poor nutrition and a lack of activity in schools is thought to contribute to the problem, many children get more activity and eat better at school than they do at home. A recent report suggests that children gain more weight over the summer than during the rest of the year. Furthermore, for many kids, fitness gains made during the school year are frequently lost over the summer. Since summer vacation is rapidly approaching, this is a critical time to help our children stay fit and healthy.

The good new is there is much we can do. Ensuring that children get plenty of healthy foods such as fruits and vegetables, reducing the consumption of added sugars, and eating appropriate portion sizes will go a long way to addressing the diet aspect of obesity. Making sure that kids of all ages have opportunities to be active while limiting time spent sitting, especially in front of a screen, are equally important.

Since children don’t make most of the decisions about their activity and diet, it is important to recognize the role that parents, grandparents, and other caregivers play. More often than not, obesity is a family issue. This means that  solving the problem is a family issue, too. Adults should model healthy behaviors by making diet and activity changes themselves. A good place to start is by turning off the TV and going outside to play or for a walk. It’s something all of us—adults and children—will benefit from.


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Is it true that you burn 100 calories when you walk or run a mile? Yes!

 

Walking and running are widely used modes of exercise to improve fitness and promote weight loss. The energy expended (calories burned) during walking or running can be directly measured in a lab or estimated based on speed and body weight. It can also be determined using one of many wearable devices and mobile apps. A commonly used estimation is that walking or running one mile elicits an energy expenditure of 100 calories.

This estimation, while crude, is interesting because of its wide use and apparent acceptance, even though it hasn’t been tested for accuracy. Research we did in the Exercise Science Lab at USC Aiken and presented at the American College of Sports Medicine annual meeting last week examined the accuracy of the 100 calories per mile estimate across a wide range of walking and running speeds. This is the topic of my Health & Fitness column in the Aiken Standard this week

100 kcals


To do this we asked subjects ranging in age from 20 to 44 years to walk or run one mile at a speed they selected on a treadmill while energy expenditure was determined. Some of the subjects walked and some ran, so the speeds ranged from 3 to 7 mph. For accuracy, we measured the air they breathed to measure how much oxygen they consumed to calculate how many calories they burned.

We found that the measured energy expenditure across all speeds was 108 calories per mile. It was higher (115 calories) during running and lower (98 calories) during walking. None of these were significantly different from the 100 calories per mile estimate.

There was a high degree of variability among subjects in energy expenditure, even at similar walking or running speed. This was due to body weight, with heavier people burning more calories when they walked or ran.

These findings are consistent with previous studies that compared the measured energy expenditure of walking and running one mile at set speeds. In our study, we allowed subjects to select their own walking or running speed, so it more closely reflects how people would exercise outside of a research setting. Research also shows that the energy expenditure during treadmill exercise was almost exactly the same as walking or running on a track, so our findings would also be applicable to walking or running on level ground.

In conclusion, the widely used estimate of 100 calories per mile appears to be accurate across a wide range of walking and running speeds. This supports using the 100 calories per mile value for estimating energy expenditure for fitness or weight loss purposes. For example, some exercise programs prescribe exercise based on calories burned rather than time or distance. And people who are trying to lose or maintain weight can use the 100 calories per mile estimate to help balance their energy intake and expenditure.

It is important to note that the 100 calories per mile estimate does not replace more accurate measurements or calculations that are done in a research or clinical setting. And wearable devices and apps are easy ways to get a good idea of how your energy expenditure during a wider range of activities. But, if you want to know how many calories you burn during a run or how long you need to walk to offset what you eat, the 100 calories per mile estimate will give you a pretty good idea.

 


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